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Coals catalyze the reduction of nitroaromatics by hydrazine and the decomposition of hydrazine
Fuel 84 (2005) 1–4 www.fuelfirst.com
Coals catalyze the reduction of nitroaromatics by hydrazine and the decomposition of hydrazine Francelys A. Medinaa, John W. Larsena,b,*, Harold H. Schoberta,*, John Stuartb a
The Energy Institute, 209 Academic Projects Building, The Pennsylvania State University, University Park, PA 16802, USA b The Department of Chemistry, 6 E. Packer Avenue, Lehigh University, Bethlehem, PA 18015, USA Received 26 February 2004; revised 19 July 2004; accepted 9 August 2004 Available online 9 September 2004
Abstract The reduction of nitroaromatics to anilines by hydrazine in refluxing isopropanol is catalyzed by: three anthracites, anthracite culm, Beulah Zap lignite, and Illinois No. 6 coal. The anthracites and the culm are very effective catalysts while the coals are less effective. The decomposition of hydrazine is also catalyzed by the anthracites and anthracite culm. q 2004 Elsevier Ltd. All rights reserved. Keywords: Anilines; Anthracites; Hydrazine
1. Introduction Carbons catalyze a variety of reactions [1–10] and are used industrially as catalysts in the preparation of phosgene and sulfuryl chloride [11]. Despite the structural resemblance of high rank coals to carbons, a literature search revealed only one report of a reaction catalyzed by an unaltered coal [12]. We have been studying the carboncatalyzed reduction of nitroaromatics by hydrazine [13] and the carbon-catalyzed decomposition of hydrazine [14]. We report here that both of these reactions [15,16] are catalyzed by coals. Nitroaromatics are smoothly reduced to anilines (see Eq. (1)) by hydrazine in a reaction that is catalyzed by metals as well as carbons [15,17]. The mechanism of the carbon-catalyzed reaction has not been determined unequivocally, but adsorption followed by electron transfer has been proposed [13]. This reaction is accompanied by a slower decomposition of hydrazine to N2 and NH3 (Eq. (2)) that is also catalyzed by carbons and metals [16,17]. * Corresponding authors. Address: The Energy Institute, The Pennsylvania State University, 209 Academic Projects Building, University Park, PA 16802, USA. Tel.: C1 215 257 8617; fax: C1 814 863 7432. E-mail address: [email protected] (J.W. Larsen). 0016-2361/$ - see front matter q 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.fuel.2004.08.005
Hydrazine decomposition has been scrutinized carefully because of hydrazine use as a monopropellant in steering thrusters [16]. We have tried both these reactions with a few coals as catalysts and observed that the coals are fair to good catalysts. 2ArNO2 C 3N2 H4 / 2ArNH2 C 3N2 C 4H2 O
(1)
3N2 H4 / N2 C 4NH3
(2)
2. Experimental 2.1. Materials The anthracites are from the Penn State Coal Sample Bank. Their elemental analyses (dry basis) are given in Table 1. All were more than 85% vitrinite. Anthracite coal waste from Eastern Pennsylvania was obtained from Waste Management and Processors, Inc. It was used after ballmilling in air to K100 mesh. Its analysis is contained in Table 2. The Beulah Zap lignite and Illinois No. 6 coal were Argonne premium samples [18]. All compounds and graphite were obtained from Fisher Scientific and were used without purification.
2
F.A. Medina et al. / Fuel 84 (2005) 1–4
Table 1 Anthracite elemental analysis and graphite content Coal
PSOC-1461
DECS-21
PSOC-1468
%C %H %N % S (org.) % O (diff.) % Mineral matter Graphite factora
70.8 1.14 0.87 0.36 K0.70 27.6 0.14
80.2 3.42 0.71 0.43 2.5 12.6 0
88.9 1.20 0.78 0.37 1.06 7.8 0.21
a
See Ref. [18].
2.2. Reactions The reduction of nitroaromatics was carried out by adding hydrazine to a refluxing (82 8C) stirred solution of the nitroaromatic in isopropanol in an atmosphere of dry N2. All reactions were carried out in a hood and appropriate precautions were taken to ensure safety when working with hydrazine. The reaction kinetics were followed by measuring gas volumes in a gas burette. In preparative reactions, 0.7 g of the catalyst were added to 0.017 mol of the nitroaromatic in 10 ml of isopropanol in a round bottom flask equipped with a magnetic stirrer ad a reflux condenser. Hydrazine hydrate (0.034 mol) or hydrazine monohydrate (0.034 mol) was then added slowly from an equilibrated addition funnel. Progress of the reaction was followed by using either a gas burette to measure the volume of gas produced or by thin layer chromatography. The identity of the gas products was established by a mixture of gas chromatography, gas chromatography–mass spectrometry, and isolation of NH3 as its hydrochloride salt.
3. Results and discussion 3.1. Nitrobenzene reduction Fig. 1 shows the time dependence of the volume of the gas produced during the reduction of nitrobenzene by hydrazine catalyzed by three anthracites and graphite. There is no Table 2 Properties of anthracite culm (%) Proximate analysis, dry basis Ash Volatile matter Fixed carbon
31.0 9.3 59.7
Ultimate analysis, dry basis Carbon Hydrogen Nitrogen Sulfur Oxygen (diff.)
62.7 1.63 0.81 0.52 3.42
Al2O3 BaO CaO Fe2O3 K2 O MgO MnO Na2O P2O5 SiO2 SrO TiO2
BET surface area 10 m2/g. Pore volume 1.14!10K2 cm3/g.
24.8 0.11 0.16 9.19 2.71 0.71 0.01 0.46 0.26 58.1 0.03 1.37
Fig. 1. Time dependence of gas evolution during the reduction of nitrobenzene by hydrazine in refluxing isopropanol catalyzed by the anthracites PSOC-1461 (&), PSOC-1468 (%), DECS-21 (,), and graphite (6).
reaction in the absence of the catalyst or hydrazine. Using an excess of hydrazine, the only product is aniline. These data demonstrate that the anthracites are catalysts for this reaction. They were selected because anthracites are the coals most structurally similar to pyrolytic carbons and carbon blacks, materials known to catalyze this reaction [13]. The graphite content of anthracites correlates with their C/H ratio and this correlation was used to estimate the graphite contents of these anthracites [18]. A word of caution is necessary: elemental analyses of anthracites may be erroneous due to the presence of adsorbed water that is not removed by normal drying and that reports as hydrogen during the combustion analysis leading to an erroneously low C/H ratio [19]. The graphite contents of the anthracites are listed in Table 1. If their catalytic ability is due to their graphite content, the reaction rates should decrease in the order PSOC 1468OPSOC 1461ODECS 21. This is not the reactivity order observed for anthracite-catalyzed reduction of nitrobenzene. Ash from these coals is not catalytic. Having demonstrated catalysis by anthracites, we became curious about the possibility of catalysis by anthracite culm, a waste product with negative value. Fig. 2 contains the time dependence of the amount of gas produced during the reduction of nitrobenzene by hydrazine catalyzed by culm, Mogul L carbon, and graphite. The culm-catalyzed reaction has a rate competitive with the other two carbons. There is no reaction in the absence of the added catalyst and no reaction in the absence of hydrazine. The reactions form aniline quantitatively if an excess of hydrazine is used. These data demonstrate that this anthracite culm is an effective catalyst for this reduction. The extent to which the catalysis is due to anthracite or the mineral matter in the culm is not known. Initial rate constants were obtained from the initial slopes of the plots of gas volume vs. time. These rate constants are essentially the same as those obtained by following the reaction for the first 20 min or by graphical differentiation of
F.A. Medina et al. / Fuel 84 (2005) 1–4
Fig. 2. Time dependence of gas evolution during the reduction of nitrobenzene by hydrazine in refluxing isopropanol catalyzed by anthracite culm (B), by mogul L (%), and by graphite (:).
the gas evolution plots. Initial rates are especially useful because they are not affected by catalyst poisoning or any changes in the catalyst caused by reactions under the strong reducing conditions used. This is especially important for carbons having reducible oxygen functionality. These data are presented in Table 3 and provide important additional insight. Using initial rate constants, the three anthracites are all better catalysts than graphite, yet at long times the anthracite-catalyzed reactions are slower (see Fig. 1). Much of the catalytic ability of the anthracites is rapidly destroyed under the reaction conditions. We have not identified the changes responsible for this. Interestingly, the culm remains effective. At either long or short time, the effectiveness of the anthracites does not correlate with their graphite content as estimated from their elemental analysis. Table 3 Initial rate constants for the reduction of 1 and nitrobenzene with hydrazine and hydrazine decomposition in refluxing isopropanol Catalyst Reduction of nitrobenzene Anthracite culm Graphite Mogul L PSOC 1468 PSOC 1461 DES 21 Reduction of 1 Illinois No. 6 coal Beulah Zap lignite Graphite Mogul L Hydrazine decomposition Anthracite culm Graphite Mogul L PSOC 1468 PSOC 1461 DES 21
3
Several carbons and Argonne premium Beulah Zap lignite and Illinois No. 6 coal were used to catalyze the hydrazine reduction of 1 in refluxing isopropanol. All of the reactions gave quantitative yields of the aniline if an excess of hydrazine was used. There was no reaction if either hydrazine or the catalyst was not present. The initial first order rate constants are given in Table 3. The reduction of nitrobenzene may go through two intermediates, each the product of a twoelectron reduction. They are in order: nitrosobenzene and hydroxylamine. It has been suggested that the carboncatalyzed reduction of nitrobenzene goes via an initial 4-electron transfer to give the hydroxylamine followed by a 2-electron transfer to give the aniline product [13]. When following the reduction of 1 by thin layer chromatography, the hydroxylamine intermediate could be detected with Beulah Zap lignite, with Illinois No. 6 coal, and with Mogul L but not with graphite. With the coals, apparently an initial 4-electron transfer reduction occurs that is followed by the 2-electron reduction of the hydroxylamine to the aniline. If the reaction proceeds through a nitrosobenzene intermediate, side reaction products would have been observed.
The initial first order rate constants are given in Table 3. The lower rank coals are not good catalysts, being 5–8 times slower than graphite. If the mechanism is adsorption and electron transfer, this is not surprising because these coals have low conductivity. But they do catalyze the reaction. 3.2. Hydrazine decomposition The decomposition of hydrazine also is catalyzed by carbons (see Figs. 3 and 4, and Table 3) [14]. Again, we
k!103 (minK1) 3.8 4.2 12.4 10.5 11.3 9.1 2.0 3.0 16 41 10.1 6.6 13.6 7.3 5.8 4.7
Fig. 3. Time dependence of gas evolution during the decomposition of hydrazine in refluxing isopropanol catalyzed by the anthracites PSOC-1461 (%), PSOC-1468 (&), DECS-21 (,), and graphite (6).
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F.A. Medina et al. / Fuel 84 (2005) 1–4
environmental impact. Coals also can catalyze reactions and should not be ignored when carbon catalysts are being considered.
Acknowledgements We are grateful to the Consortium for Premium Carbon Products from Coal, the Pennsylvania Ben Franklin program, and Crompton and Knowles Inc. for support of this work. We are pleased to acknowledge the gift of anthracite culm from Waste Management and Processors, Inc.
References Fig. 4. Time dependence of gas evolution during the decomposition of hydrazine in refluxing isopropanol catalyzed by anthracite culm (B), by mogul L (%), and by graphite (:).
tried anthracites because of their structural similarity to carbons. The gas evolution data shown in Fig. 3 demonstrate catalysis. No gas was evolved in the absence of the anthracites or of hydrazine. The catalytic activity of the anthracites at short and long time is in the same order as their estimated graphite contents. Again, their catalytic activity decreases at longer reaction times indicating changes in the anthracite structure. Having been successful with anthracites, the anthracite culm was investigated. The anthracite culm was an effective catalyst. The catalytic effectiveness of both the graphite and culm decreases as the reaction proceeds while the Mogul L carbon is unaffected. The mechanism of hydrazine decomposition on carbons is not known so there is no point in speculating about reaction pathways.
4. Summary Carbons are attractive catalytic materials because of their low cost, easily tailored properties, and low
[1] Weiss DE. Proceedings of the fifth conference on carbon 1962;1:65. [2] Hassler JW. Activated carbon. New York: Chemical Publishing Co.; 1963. [3] Coughlin RW. Ind Eng Chem Prod Res Dev 1969;8:12. [4] Coughlin RW. Proceedings of the fourth international congress on catalysis 1971;2:322. [5] Trimm DL. In: Catalysis, vol. 4, 1981. p. Cp8. [6] Tripathi VS, Ramachandran PK. Defense Sci J 1985;35:115. [7] Juntgen H, Kuhl H. In: Thrower PA, editor. Chemistry and physics of carbon, 22. New York: Marcel Dekker; 1989. Cp2. [8] Kalra KC, Katyal P, Singh KC. J Sci Ind Res 1989;48:186. [9] Spiro M. Catal Today 1990;7:167. [10] Radovic Lr, Rodriguez-Reinoso F. In: Thrower PA, editor. Chemistry and physics of carbon, 25. New York: Marcel Dekker; 1997. p. 243. [11] Kroschwitz JI. Kirk_othmer concise encyclopedia of chemical technology. New York: Wiley; 1999. [12] Bezulgi DV, Kutsakov FM. Ukraninskii Khem Zhur 1937;12:26. [13] Larsen JW, Freund M, Kim KY, Sidovar M, Stuart JL. Carbon 2000; 38:655. [14] Larsen JW, Jandzinski J, Sidovar M, Stuart JL. Carbon 2001;39:473. [15] Han BH, Shin DH, Lee HR, Ro BH. Bull Korean Chem Soc 1989;10: 315. [16] Schmidt EW. Hydrazine and its derivatives: preparation, properties, applications, 2nd ed. New York: Wiley Interscience; 2001. [17] Furst A, Berlo RC, Hooton S. Chem Rev 1965;65:51. [18] Jiang YJ, Solum MS, Pugmire RJ, Grant DM, Schobert HH, Pappano PJ. Energy Fuels 2002;16:1296. [19] Aso H, Matsuoka K, Tomita A. Energy Fuels 2003;17:1244. [20] Vorres K. Energy Fuels 1990;4:420.
Coals catalyze the reduction of nitroaromatics by hydrazine and the decomposition of hydrazine Francelys A. Medinaa, John W. Larsena,b,*, Harold H. Schoberta,*, John Stuartb a
The Energy Institute, 209 Academic Projects Building, The Pennsylvania State University, University Park, PA 16802, USA b The Department of Chemistry, 6 E. Packer Avenue, Lehigh University, Bethlehem, PA 18015, USA Received 26 February 2004; revised 19 July 2004; accepted 9 August 2004 Available online 9 September 2004
Abstract The reduction of nitroaromatics to anilines by hydrazine in refluxing isopropanol is catalyzed by: three anthracites, anthracite culm, Beulah Zap lignite, and Illinois No. 6 coal. The anthracites and the culm are very effective catalysts while the coals are less effective. The decomposition of hydrazine is also catalyzed by the anthracites and anthracite culm. q 2004 Elsevier Ltd. All rights reserved. Keywords: Anilines; Anthracites; Hydrazine
1. Introduction Carbons catalyze a variety of reactions [1–10] and are used industrially as catalysts in the preparation of phosgene and sulfuryl chloride [11]. Despite the structural resemblance of high rank coals to carbons, a literature search revealed only one report of a reaction catalyzed by an unaltered coal [12]. We have been studying the carboncatalyzed reduction of nitroaromatics by hydrazine [13] and the carbon-catalyzed decomposition of hydrazine [14]. We report here that both of these reactions [15,16] are catalyzed by coals. Nitroaromatics are smoothly reduced to anilines (see Eq. (1)) by hydrazine in a reaction that is catalyzed by metals as well as carbons [15,17]. The mechanism of the carbon-catalyzed reaction has not been determined unequivocally, but adsorption followed by electron transfer has been proposed [13]. This reaction is accompanied by a slower decomposition of hydrazine to N2 and NH3 (Eq. (2)) that is also catalyzed by carbons and metals [16,17]. * Corresponding authors. Address: The Energy Institute, The Pennsylvania State University, 209 Academic Projects Building, University Park, PA 16802, USA. Tel.: C1 215 257 8617; fax: C1 814 863 7432. E-mail address: [email protected] (J.W. Larsen). 0016-2361/$ - see front matter q 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.fuel.2004.08.005
Hydrazine decomposition has been scrutinized carefully because of hydrazine use as a monopropellant in steering thrusters [16]. We have tried both these reactions with a few coals as catalysts and observed that the coals are fair to good catalysts. 2ArNO2 C 3N2 H4 / 2ArNH2 C 3N2 C 4H2 O
(1)
3N2 H4 / N2 C 4NH3
(2)
2. Experimental 2.1. Materials The anthracites are from the Penn State Coal Sample Bank. Their elemental analyses (dry basis) are given in Table 1. All were more than 85% vitrinite. Anthracite coal waste from Eastern Pennsylvania was obtained from Waste Management and Processors, Inc. It was used after ballmilling in air to K100 mesh. Its analysis is contained in Table 2. The Beulah Zap lignite and Illinois No. 6 coal were Argonne premium samples [18]. All compounds and graphite were obtained from Fisher Scientific and were used without purification.
2
F.A. Medina et al. / Fuel 84 (2005) 1–4
Table 1 Anthracite elemental analysis and graphite content Coal
PSOC-1461
DECS-21
PSOC-1468
%C %H %N % S (org.) % O (diff.) % Mineral matter Graphite factora
70.8 1.14 0.87 0.36 K0.70 27.6 0.14
80.2 3.42 0.71 0.43 2.5 12.6 0
88.9 1.20 0.78 0.37 1.06 7.8 0.21
a
See Ref. [18].
2.2. Reactions The reduction of nitroaromatics was carried out by adding hydrazine to a refluxing (82 8C) stirred solution of the nitroaromatic in isopropanol in an atmosphere of dry N2. All reactions were carried out in a hood and appropriate precautions were taken to ensure safety when working with hydrazine. The reaction kinetics were followed by measuring gas volumes in a gas burette. In preparative reactions, 0.7 g of the catalyst were added to 0.017 mol of the nitroaromatic in 10 ml of isopropanol in a round bottom flask equipped with a magnetic stirrer ad a reflux condenser. Hydrazine hydrate (0.034 mol) or hydrazine monohydrate (0.034 mol) was then added slowly from an equilibrated addition funnel. Progress of the reaction was followed by using either a gas burette to measure the volume of gas produced or by thin layer chromatography. The identity of the gas products was established by a mixture of gas chromatography, gas chromatography–mass spectrometry, and isolation of NH3 as its hydrochloride salt.
3. Results and discussion 3.1. Nitrobenzene reduction Fig. 1 shows the time dependence of the volume of the gas produced during the reduction of nitrobenzene by hydrazine catalyzed by three anthracites and graphite. There is no Table 2 Properties of anthracite culm (%) Proximate analysis, dry basis Ash Volatile matter Fixed carbon
31.0 9.3 59.7
Ultimate analysis, dry basis Carbon Hydrogen Nitrogen Sulfur Oxygen (diff.)
62.7 1.63 0.81 0.52 3.42
Al2O3 BaO CaO Fe2O3 K2 O MgO MnO Na2O P2O5 SiO2 SrO TiO2
BET surface area 10 m2/g. Pore volume 1.14!10K2 cm3/g.
24.8 0.11 0.16 9.19 2.71 0.71 0.01 0.46 0.26 58.1 0.03 1.37
Fig. 1. Time dependence of gas evolution during the reduction of nitrobenzene by hydrazine in refluxing isopropanol catalyzed by the anthracites PSOC-1461 (&), PSOC-1468 (%), DECS-21 (,), and graphite (6).
reaction in the absence of the catalyst or hydrazine. Using an excess of hydrazine, the only product is aniline. These data demonstrate that the anthracites are catalysts for this reaction. They were selected because anthracites are the coals most structurally similar to pyrolytic carbons and carbon blacks, materials known to catalyze this reaction [13]. The graphite content of anthracites correlates with their C/H ratio and this correlation was used to estimate the graphite contents of these anthracites [18]. A word of caution is necessary: elemental analyses of anthracites may be erroneous due to the presence of adsorbed water that is not removed by normal drying and that reports as hydrogen during the combustion analysis leading to an erroneously low C/H ratio [19]. The graphite contents of the anthracites are listed in Table 1. If their catalytic ability is due to their graphite content, the reaction rates should decrease in the order PSOC 1468OPSOC 1461ODECS 21. This is not the reactivity order observed for anthracite-catalyzed reduction of nitrobenzene. Ash from these coals is not catalytic. Having demonstrated catalysis by anthracites, we became curious about the possibility of catalysis by anthracite culm, a waste product with negative value. Fig. 2 contains the time dependence of the amount of gas produced during the reduction of nitrobenzene by hydrazine catalyzed by culm, Mogul L carbon, and graphite. The culm-catalyzed reaction has a rate competitive with the other two carbons. There is no reaction in the absence of the added catalyst and no reaction in the absence of hydrazine. The reactions form aniline quantitatively if an excess of hydrazine is used. These data demonstrate that this anthracite culm is an effective catalyst for this reduction. The extent to which the catalysis is due to anthracite or the mineral matter in the culm is not known. Initial rate constants were obtained from the initial slopes of the plots of gas volume vs. time. These rate constants are essentially the same as those obtained by following the reaction for the first 20 min or by graphical differentiation of
F.A. Medina et al. / Fuel 84 (2005) 1–4
Fig. 2. Time dependence of gas evolution during the reduction of nitrobenzene by hydrazine in refluxing isopropanol catalyzed by anthracite culm (B), by mogul L (%), and by graphite (:).
the gas evolution plots. Initial rates are especially useful because they are not affected by catalyst poisoning or any changes in the catalyst caused by reactions under the strong reducing conditions used. This is especially important for carbons having reducible oxygen functionality. These data are presented in Table 3 and provide important additional insight. Using initial rate constants, the three anthracites are all better catalysts than graphite, yet at long times the anthracite-catalyzed reactions are slower (see Fig. 1). Much of the catalytic ability of the anthracites is rapidly destroyed under the reaction conditions. We have not identified the changes responsible for this. Interestingly, the culm remains effective. At either long or short time, the effectiveness of the anthracites does not correlate with their graphite content as estimated from their elemental analysis. Table 3 Initial rate constants for the reduction of 1 and nitrobenzene with hydrazine and hydrazine decomposition in refluxing isopropanol Catalyst Reduction of nitrobenzene Anthracite culm Graphite Mogul L PSOC 1468 PSOC 1461 DES 21 Reduction of 1 Illinois No. 6 coal Beulah Zap lignite Graphite Mogul L Hydrazine decomposition Anthracite culm Graphite Mogul L PSOC 1468 PSOC 1461 DES 21
3
Several carbons and Argonne premium Beulah Zap lignite and Illinois No. 6 coal were used to catalyze the hydrazine reduction of 1 in refluxing isopropanol. All of the reactions gave quantitative yields of the aniline if an excess of hydrazine was used. There was no reaction if either hydrazine or the catalyst was not present. The initial first order rate constants are given in Table 3. The reduction of nitrobenzene may go through two intermediates, each the product of a twoelectron reduction. They are in order: nitrosobenzene and hydroxylamine. It has been suggested that the carboncatalyzed reduction of nitrobenzene goes via an initial 4-electron transfer to give the hydroxylamine followed by a 2-electron transfer to give the aniline product [13]. When following the reduction of 1 by thin layer chromatography, the hydroxylamine intermediate could be detected with Beulah Zap lignite, with Illinois No. 6 coal, and with Mogul L but not with graphite. With the coals, apparently an initial 4-electron transfer reduction occurs that is followed by the 2-electron reduction of the hydroxylamine to the aniline. If the reaction proceeds through a nitrosobenzene intermediate, side reaction products would have been observed.
The initial first order rate constants are given in Table 3. The lower rank coals are not good catalysts, being 5–8 times slower than graphite. If the mechanism is adsorption and electron transfer, this is not surprising because these coals have low conductivity. But they do catalyze the reaction. 3.2. Hydrazine decomposition The decomposition of hydrazine also is catalyzed by carbons (see Figs. 3 and 4, and Table 3) [14]. Again, we
k!103 (minK1) 3.8 4.2 12.4 10.5 11.3 9.1 2.0 3.0 16 41 10.1 6.6 13.6 7.3 5.8 4.7
Fig. 3. Time dependence of gas evolution during the decomposition of hydrazine in refluxing isopropanol catalyzed by the anthracites PSOC-1461 (%), PSOC-1468 (&), DECS-21 (,), and graphite (6).
4
F.A. Medina et al. / Fuel 84 (2005) 1–4
environmental impact. Coals also can catalyze reactions and should not be ignored when carbon catalysts are being considered.
Acknowledgements We are grateful to the Consortium for Premium Carbon Products from Coal, the Pennsylvania Ben Franklin program, and Crompton and Knowles Inc. for support of this work. We are pleased to acknowledge the gift of anthracite culm from Waste Management and Processors, Inc.
References Fig. 4. Time dependence of gas evolution during the decomposition of hydrazine in refluxing isopropanol catalyzed by anthracite culm (B), by mogul L (%), and by graphite (:).
tried anthracites because of their structural similarity to carbons. The gas evolution data shown in Fig. 3 demonstrate catalysis. No gas was evolved in the absence of the anthracites or of hydrazine. The catalytic activity of the anthracites at short and long time is in the same order as their estimated graphite contents. Again, their catalytic activity decreases at longer reaction times indicating changes in the anthracite structure. Having been successful with anthracites, the anthracite culm was investigated. The anthracite culm was an effective catalyst. The catalytic effectiveness of both the graphite and culm decreases as the reaction proceeds while the Mogul L carbon is unaffected. The mechanism of hydrazine decomposition on carbons is not known so there is no point in speculating about reaction pathways.
4. Summary Carbons are attractive catalytic materials because of their low cost, easily tailored properties, and low
[1] Weiss DE. Proceedings of the fifth conference on carbon 1962;1:65. [2] Hassler JW. Activated carbon. New York: Chemical Publishing Co.; 1963. [3] Coughlin RW. Ind Eng Chem Prod Res Dev 1969;8:12. [4] Coughlin RW. Proceedings of the fourth international congress on catalysis 1971;2:322. [5] Trimm DL. In: Catalysis, vol. 4, 1981. p. Cp8. [6] Tripathi VS, Ramachandran PK. Defense Sci J 1985;35:115. [7] Juntgen H, Kuhl H. In: Thrower PA, editor. Chemistry and physics of carbon, 22. New York: Marcel Dekker; 1989. Cp2. [8] Kalra KC, Katyal P, Singh KC. J Sci Ind Res 1989;48:186. [9] Spiro M. Catal Today 1990;7:167. [10] Radovic Lr, Rodriguez-Reinoso F. In: Thrower PA, editor. Chemistry and physics of carbon, 25. New York: Marcel Dekker; 1997. p. 243. [11] Kroschwitz JI. Kirk_othmer concise encyclopedia of chemical technology. New York: Wiley; 1999. [12] Bezulgi DV, Kutsakov FM. Ukraninskii Khem Zhur 1937;12:26. [13] Larsen JW, Freund M, Kim KY, Sidovar M, Stuart JL. Carbon 2000; 38:655. [14] Larsen JW, Jandzinski J, Sidovar M, Stuart JL. Carbon 2001;39:473. [15] Han BH, Shin DH, Lee HR, Ro BH. Bull Korean Chem Soc 1989;10: 315. [16] Schmidt EW. Hydrazine and its derivatives: preparation, properties, applications, 2nd ed. New York: Wiley Interscience; 2001. [17] Furst A, Berlo RC, Hooton S. Chem Rev 1965;65:51. [18] Jiang YJ, Solum MS, Pugmire RJ, Grant DM, Schobert HH, Pappano PJ. Energy Fuels 2002;16:1296. [19] Aso H, Matsuoka K, Tomita A. Energy Fuels 2003;17:1244. [20] Vorres K. Energy Fuels 1990;4:420.