氢气还原Co<sub>3</sub>O<sub>4</sub>制备纳米Co及其乳酸乙酯加氢反应的研究

摘要

Co纳米材料是乳酸乙酯加氢制备1，2-丙二醇的重要催化剂。合成了不同形貌的Co₃O₄纳米材料，利用氢气热还原的方法制备了不同形貌的Co纳米粒子。TEM结果表明低温下还原不同形貌的Co₃O₄制备得到的Co纳米材料形貌保持不变；TPR结果表明颗粒状的纳米Co₃O₄比棒状的更易在低温下还原得到纳米Co。通过对乳酸乙酯加氢反应的测试表明，低温还原制备的Co纳米颗粒比纳米棒具有更高的加氢活性。此外，考察了Co₃O₄的还原温度对纳米Co颗粒中金属晶型的影响，XRD和TEM结果表明低温还原得到的Co纳米颗粒中先出现hcp晶型的金属Co，随着还原温度的升高，hcp晶型金属Co逐渐向fcc晶型转变。乳酸乙酯加氢反应结果表明，随着还原温度的增加，Co纳米颗粒的乳酸乙酯加氢转化率先增加后减小，在300℃时达到最大值71%，即低温下还原得到的hcp晶型有利于乳酸乙酯加氢，而高温下生成的fcc晶型不利于乳酸乙酯加氢，此外，高温下催化剂颗粒的聚集也可能造成乳酸乙酯加氢活性降低。

	Service

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	Email Alert
	RSS
	作者相关文章
	张晓鹏
	韩金玉
	王华
	刘晓
	赵建康

关键词：乳酸乙酯加氢 Co纳米粒子还原温度晶型

Abstract：

Nano-cobalt materials play an important role in the hydrogenation of ethyl lactate to 1,2-PDO. Herein, Co₃O₄ nanomaterials with different morphologies were synthesized, which were further reduced under hydrogen atmosphere to form nano-cobalt. The TEM results indicated that nano-cobalt materials obtained from Co₃O₄ at a low temperature kept original morphologies. The TPR results showed that the Co₃O₄ nanoparticles reduced at a low temperature were easier to generate metal cobalt than Co₃O₄ nanorods. Hence, cobalt nanoparticles gave an excellent conversion for the hydrogenation of ethyl lactate while cobalt nanorods had no activity. Furthermore, the effect of reduction temperature of Co₃O₄ on the nano-cobalt crystal structures was investigated. XRD and TEM results showed that the hcp phase can be produced at a lower temperature. With increasing the reduction temperature, the transformation from hcp phase to fcc phase would take place. The effect of cobalt nanoparticles reduced at different temperature on the performance of hydrogenation of ethyl lactate was studied. Experiments proved that the cobalt nanoparticles had a positive effect on the hydrogenation performance till the reduction temperature increased to 300℃ with a 71% conversion of ethyl lactate. However, when the reduction temperature increased continually, the conversion of ethyl lactate decreased. It indicated that the hcp phase was beneficial to the hydrogenation of ethyl lactate while the fcc phase hampered the hydrogenation of ethyl lactate. In addition, aggregation may also lower the catalytic activity above 300℃.

Keywords： ethyl lactate； hydrogenation； cobalt nanoparticles； reduction temperature； crystal structures

Received 2016-04-01;

Fund:

国家自然科学基金（21076152，21276191）；教育部博士点基金（2100032110018）。

Corresponding Authors: 王华,E-mail:tjuwanghua@tju.edu.com。 Email: tjuwanghua@tju.edu.com

About author: 张晓鹏,女,硕士研究生,现从事生物质转化的研究。

引用本文:

张晓鹏, 韩金玉, 王华, 刘晓, 赵建康.氢气还原Co₃O₄制备纳米Co及其乳酸乙酯加氢反应的研究[J]. 化学工业与工程, 2018,35(1): 8-14

Zhang Xiaopeng, Han Jinyu, Wang Hua, Liu Xiao, Zhao Jiankang.Reduction of Co₃O₄ by Hydrogen to Prepare Nano-Cobalt and the Study of Hydrogenation of Ethyl Lactate[J]. Chemcial Industry and Engineering, 2018,35(1): 8-14

[1] Ruppert A M, Weinberg K, Palkovits R. Hydrogenolysis goes bio:From carbohydrates and sugar alcohols to platform chemicals[J]. Angewandte Chemie International Edition in English, 2012, 51(11):2564-2601
[2] Besson M, Gallezot P, Pinel C. Conversion of biomass into chemicals over metal catalysts[J]. Chemical Reviews, 2014, 114(3):1827-1870
[3] Feng J, Xiong W, Jia Y, et al. Hydrogenation of ethyl lactate over ruthenium catalysts in an additive-free catalytic system[J]. Reaction Kinetics, Mechanisms and Catalysis, 2011, 104(1):89-97
[4] Luo G, Yan S, Qiao M, et al. Effect of promoters on the structures and properties of the RuB/γ-Al₂O₃ catalyst[J]. Journal of Molecular Catalysis A:Chemical, 2005, 230(1/2):69-77
[5] Luo G, Yan S, Qiao M, et al. Effect of tin on Ru-B/γ-Al₂O₃ catalyst for the hydrogenation of ethyl lactate to 1,2-propanediol[J]. Applied Catalysis A:General, 2004, 275(1/2):95-102
[6] Joseyphusa R J, Matsumotob T, Takahashi H, et al. Designed synthesis of cobalt and its alloys by polyol process[J]. Journal of Solid State Chemistry, 2007, 180(11):3008-3018
[7] Osorio-Cantillo C, Santiago-Miranda A N, Perales-Perez O, et al. Size-and phase-controlled synthesis of cobalt nanoparticles for potential biomedical applications[J]. Journal of Applied Physics, 2012, 111(7):2532-2595
[8] Yang J, Liu Q, Sun W. Co(Ⅱ)-doped MOF-5 nano/microcrystals:Solvatochromic behaviour, sensing solvent molecules and gas sorption property[J]. Journal of Solid State Chemistry, 2014, 218:50-55
[9] 龚晓钟, 汤皎宁, 李均钦, 等. 微波法制备金属钴纳米晶棒及其表征[J]. 应用化学, 2005, 22(12):1291-1294 Gong Xiaozhong, Tang Jiaoning, Li Junqin, et al. Preparation of cobalt nanocrystals rods by microwave method and characterization[J]. Applied Chemistry, 2005, 22(12):1291-1294(in Chinese)
[10] Xue J, Cui F, Huang Z, et al. Liquid phase hydrogenolysis of biomass-derived lactate to 1,2-propanediol over silica supported cobalt nanocatalyst[J]. Chinese Journal of Chemistry, 2011, 29(7):1319-1325
[11] Ma X, Sun D, Zhao F, et al. Liquid phase hydrogenation of biomass-derived ethyl lactate to propane-1,2-diol over a highly active CoB amorphous catalyst[J]. Catalysis Communications, 2015, 60:124-128
[12] Liu Q, Cao X, Wang T, et al. Synthesis of shape-controllable cobalt nanoparticles and their shape-dependent performance in glycerol hydrogenolysis[J]. RSC Advances, 2015, 5(7):4861-4871
[13] Xie X, Shen W. Morphology control of cobalt oxide nanocrystals for promoting their catalytic performance[J]. Nanoscale, 2009, 1(1):50-60
[14] Xie X, Li Y, Liu Z, et al. Low-Temperature oxidation of CO catalysed by Co₃O₄ nanorods[J]. Nature, 2009, 458(7239):746-749
[15] Wang W, Lin H, Chen Y. Carbon monoxide hydrogenation on cobalt/zeolite catalysts[J]. Journal of Porous Materials, 2005, 12(1):5-12
[16] Khodakov A Y, Lynch J, Bazin D, et al. Reducibility of cobalt species in silica-supported Fischer-Tropsch catalysts[J]. Journal of Catalysis, 1997, 168(1):16-25
[17] Shi L, Zeng C, Lin Q, et al. Citric acid assisted one-step synthesis of highly dispersed metallic Co/SiO₂ without further reduction:As-Prepared Co/SiO₂ catalysts for Fischer-Tropsch synthesis[J]. Catalysis Today, 2014, 228:206-211
[18] Bulavchenko O A, Cherepanova S V, Malakhov V V, et al. In situ XRD study of nanocrystalline cobalt oxide reduction[J]. Kinetics and Catalysis, 2009, 50(2):192-198
[19] Potoczna-Petru D, Kepinski L. Reduction study of Co₃O₄ model catalyst by electron microscopy[J]. Catalysis Letters, 2001, 73(1):41-46
[20] Huang L, Zhu Y, Zheng H, et al. Vapor-Phase hydrogenolysis of biomass-derived lactate to 1,2-propanediol over supported metal catalysts[J]. Applied Catalysis A:General, 2008, 349(1/2):204-211
[21] Ducreux O, Rebours B, Lynch J, et al. Microstructure of supported cobalt Fischer-Tropsch catalysts[J]. Oil & Gas Science and Technology, 2008, 64(1):49-62
[22] Xue J, Fang C, Huang W, et al. Effect of metal additives on structure and properties of a Co/SiO₂ hydrogenation catalyst[J]. Chinese Journal of Catalysis, 2012, 33(9/10):1642-1649