铝添加量对Cu/ZnO/Al_2O_3甲醇合成催化剂性能的影响
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摘要
采用分步沉淀法制备出一系列不同铝含量的催化剂样品,通过X射线衍射(XRD)、热重-质谱(TG-MS)、荧光光谱仪(XRF)、N_2物理吸附、氢气程序升温还原(H_2-TPR)对样品进行表征,考察了不同铝添加量对铜基甲醇催化剂性能的影响。结果表明,铝元素的添加对前驱物中碱式碳酸盐组分产生作用,促进了焙烧后样品中高温碳酸盐的形成,进而影响到催化剂的性能。随着铝元素的添加,焙烧后催化剂的比表面积、催化剂活性和热稳定性均有增加。当Al~(3+)/(Cu~(2+)+Zn~(2+)+Al~(3+))物质的量比增加至30%时,催化剂在230℃、4 MPa和合成气(13%CO、1.2%CO_2、80%H_2、5.8%Ar)的评价条件下,热处理前后的CO转化率分别为76%和67%,仍保持着较高的活性和热稳定性。
The objective of this work is to investigate the effect of Al contents on the performance of methanol-synthesis catalysts. A series of catalyst samples with various Al contents were prepared with fractional precipitation method, and characterized with methods including XRD, TG-MS, XRF, N_2 physisorption and H_2-TPR. Results show that Al addition affected the subcarbonate structure in precursors, which promoted the formation of high temperature carbonates, and thus has an effect on the catalyst performance. With Al addition, the BET surface area of the calcined catalysts, catalyst activity and thermostability increased to different degrees. When the molar ratio of Al~(3+) in catalyst increased to 30%, the CO conversions before and after heat treatment were 76% and 67%, respectively, at the conditions of 230 ℃, 4 MPa and syngas composition of 13%CO, 1.2%CO_2, 80%H_2 and 5.8%Ar. The catalyst sample with 0.3 of Al~(3+)/(Cu~(2+)+Zn~(2+)+Al~(3+)) molar ratio remains good catalyst performance.
The objective of this work is to investigate the effect of Al contents on the performance of methanol-synthesis catalysts. A series of catalyst samples with various Al contents were prepared with fractional precipitation method, and characterized with methods including XRD, TG-MS, XRF, N_2 physisorption and H_2-TPR. Results show that Al addition affected the subcarbonate structure in precursors, which promoted the formation of high temperature carbonates, and thus has an effect on the catalyst performance. With Al addition, the BET surface area of the calcined catalysts, catalyst activity and thermostability increased to different degrees. When the molar ratio of Al~(3+) in catalyst increased to 30%, the CO conversions before and after heat treatment were 76% and 67%, respectively, at the conditions of 230 ℃, 4 MPa and syngas composition of 13%CO, 1.2%CO_2, 80%H_2 and 5.8%Ar. The catalyst sample with 0.3 of Al~(3+)/(Cu~(2+)+Zn~(2+)+Al~(3+)) molar ratio remains good catalyst performance.
引文
[1] XU X, LIU Y, ZHANG F, DI W, ZHANG Y L. Clean coal technologies in China based on methanol platform[J]. Catal Today, 2017, 298: 61-68.
[2] ZHANG F, FAN M, HUANG X, ARGYLE M, ZHANG B, TOWLER B, ZHANG Y L. Catalytic gasification of a Powder River Basin coal with CO2 and H2O mixtures[J]. Fuel Process Technol, 2017, 161: 145-154.
[3] 夏王琼, 唐浩东, 林胜达, 岑亚青, 刘化章. 甲醇合成Cu/ZnO催化剂前驱体的物相转变[J]. 催化学报, 2009, 30(9): 879-884.(XIA Wang-xiong, TANG Hao-dong, LIN Sheng-da, CEN Ya-qing, LIU Hua-zhang. Phase transformation of Cu/ZnO catalyst precursors for methanol synthesis[J]. Chin J Catal, 2009, 30(9): 879-884.)
[4] 刘艳霞, 王丽丽, 王琪, 陈爱平, 侯功淮, 杨意泉. γ-Al2O3对铜基甲醇合成催化剂的促进作用[J]. 厦门大学学报(自然科学版), 2007, 46(5): 661-664.(LIU Yan-xia, WANG Li-li, WANG Qi, CHEN Ai-ping, HOU Gong-huai, YANG Yi-quan. The promoting effect of γ-Al2O3 on copper-based catalysts for methanol synthesis[J]. J Xiamen Univ, Nat Sci, 2007, 46(5): 661-664.)
[5] BEHRENS M. Meso-and nano-structuring of industrial Cu/ZnO/(Al2O3) catalysts[J]. J Catal, 2009, 267(1): 24-29.
[6] BEHRENS M. Coprecipitation: An excellent tool for the synthesis of supported metal catalysts-From the understanding of the well known recipes to new materials[J]. Catal Today, 2015, 246: 46-54.
[7] 林胜达, 唐浩东, 吕兆坡, 刘采来, 岑亚青, 刘化章. 沉淀方法对铜基甲醇合成催化剂前驱体及其性能的影响[J]. 催化学报, 2010, 31(10): 1257-1262.(LIN Sheng-da, TANG Hao-dong, LV Zhao-bo, LIU Cai-lai, CEN Ya-qing, LIU Hua-zhang. Influence of precipitation methods on precursors and properties of Cu-based catalyst for methanol synthesis[J]. Chin J Catal, 2010, 31(10): 1257-1262.)
[8] BALTES C, VUKOJEVI. Correlations between synthesis, precursor, and catalyst structure and activity of a large set of CuO/ZnO/Al2O3 catalysts for methanol synthesis[J]. J Catal, 2008, 258(2): 334-344.
[9] BEHRENS M, ZANDER S, KURR P, JACOBSEN N, SENKER J, KOCH G, RESSLER T, FISCHER R, SCHLOGL R. Performance improvement of nanocatalysts by promoter-induced defects in the support material: Methanol synthesis over Cu/ZnO:Al[J]. J Am Chem Soc, 2013, 135(16): 6061-6068.
[10] 李忠, 郭启海, 张小兵, 郑华艳, 范辉, 谢克昌. 前驱体物相转变对浆态床合成甲醇催化剂活性的影响[J]. 高等学校化学学报, 2009, 30: 2215-2221.(LI Zhong, GUO Qi-hai, ZHANG Xiao-bing, ZHENG Hua-yan, FAN Hui, XIE Ke-chang. Influence of the precursor phase transition on the catalyst activity in slurry methanol synthesis[J]. Chem J Chin Univ, 2009, 30: 2215-2221.)
[11] BEHRENS M, KASATKIN I, KüHL S. Phase-pure Cu,Zn,Al hydrotalcite-like materials as precursors for copper rich Cu/ZnO/Al2O3 catalysts[J]. Chem Mater, 2010, 22(2): 386-397.
[12] BAHMANI M, VASHEGHANI FARAHANI B, SAHEBDELFAR S. Preparation of high performance nano-sized Cu/ZnO/Al2O3 methanol synthesis catalyst via aluminum hydrous oxide sol[J]. Appl Catal A: Gen, 2016, 520: 178-187.
[13] CHU Z, CHEN H, YU Y, WANG Q, FANG D Y. Surfactant-assisted preparation of Cu/ZnO/Al2O3 catalyst for methanol synthesis from syngas[J]. J Mol Catal A: Chem, 2013, 366: 48-53.
[14] 李忠, 张小兵, 郭启海, 刘岩, 郑华艳. 沉淀及老化温度对浆态床合成甲醇铜锌铝催化剂活性及稳定性的影响[J]. 燃料化学学报, 2012, 40(5): 569-575.(LI Zhong, ZHANG Xiao-bing, GUO Qi-hai, LIU Yan, ZHENG Hua-yan. Influence of precipitation and aging temperature on the performance of CuO/ZnO/Al2O3 catalyst for methanol synthesis in slurry reactor[J]. J Fuel Chem Technol, 2012, 40(5): 569-575.)
[15] SCHUMANN J, TARASOV A, THOMAS N, SCHLOGL R, BEHRENS M. Cu,Zn-based catalysts for methanol synthesis: On the effect of calcination conditions and the part of residual carbonates[J]. Appl Catal A: Gen, 2016, 516: 117-126.
[16] ZHANG F, ZHANG Y L, LIU Y, GASEM K, CHEN J Y, CHIANG F G, WANG Y G, FAN M. Synthesis of Cu/Zn/Al/Mg catalysts on methanol production by different precipitation methods[J]. Mol Catal, 2017, 441: 190-198.
[17] MILLAR G J, HOLM I H, UWINS P J R, DRENNAN J. Characterization of precursors to methanol synthesis catalysts Cu/ZnO system[J]. J Chem Soc Faraday Trans, 1998, 94(4): 593-600.
[18] BEMS B, SCHUR M, DASSENOY A, JUNKES H, HEREIN D, SCHLOGL R. Relations between synthesis and microstructural properties of copper/zinc hydroxycarbonates[J]. Chem-Eur J, 2003, 9(9): 2039-2052.
[19] GAO P, LI F, ZHAN H, ZHAO N, XIAO F, WEI W, ZHONG L, WANG H, SUN Y H. Influence of Zr on the performance of Cu/Zn/Al/Zr catalysts via hydrotalcite-like precursors for CO2 hydrogenation to methanol[J]. J Catal, 2013, 298: 51-60.
[20] KüHL S, TARASOV A, ZANDER S, KASATKIN I, BEHRENS M. Cu-based catalyst resulting from a Cu,Zn,Al hydrotalcite-like compound: A microstructural, thermoanalytical, and in-situ XAS study[J]. Chem-Eur J, 2014, 20(13): 3782-3792.
[21] BEHRENS M. Promoting the synthesis of methanol: Understanding the requirements for an industrial catalyst for the conversion of CO2[J]. Angew Chem Int Ed, 2016, 55(48): 14906-14908.Effect of aluminum proportion on the Cu/ZnO/Al2O3 methanol-synthesis catalystZHANG Fan FENG Bo DUAN Xue-lei LI Jing CHEN Jing-yun ZHANG Yu-long SUN Qi 铝元素的添加促进了高温碳酸盐的形成,进而影响到催化剂性能。J Fuel Chem Technol, 2019, 47(3): 329-337 富含介孔Ni/W-USY/Al2O3催化剂的费托蜡加氢裂化性能韩磊黄传峰刘树伟程秋香常方圆
[2] ZHANG F, FAN M, HUANG X, ARGYLE M, ZHANG B, TOWLER B, ZHANG Y L. Catalytic gasification of a Powder River Basin coal with CO2 and H2O mixtures[J]. Fuel Process Technol, 2017, 161: 145-154.
[3] 夏王琼, 唐浩东, 林胜达, 岑亚青, 刘化章. 甲醇合成Cu/ZnO催化剂前驱体的物相转变[J]. 催化学报, 2009, 30(9): 879-884.(XIA Wang-xiong, TANG Hao-dong, LIN Sheng-da, CEN Ya-qing, LIU Hua-zhang. Phase transformation of Cu/ZnO catalyst precursors for methanol synthesis[J]. Chin J Catal, 2009, 30(9): 879-884.)
[4] 刘艳霞, 王丽丽, 王琪, 陈爱平, 侯功淮, 杨意泉. γ-Al2O3对铜基甲醇合成催化剂的促进作用[J]. 厦门大学学报(自然科学版), 2007, 46(5): 661-664.(LIU Yan-xia, WANG Li-li, WANG Qi, CHEN Ai-ping, HOU Gong-huai, YANG Yi-quan. The promoting effect of γ-Al2O3 on copper-based catalysts for methanol synthesis[J]. J Xiamen Univ, Nat Sci, 2007, 46(5): 661-664.)
[5] BEHRENS M. Meso-and nano-structuring of industrial Cu/ZnO/(Al2O3) catalysts[J]. J Catal, 2009, 267(1): 24-29.
[6] BEHRENS M. Coprecipitation: An excellent tool for the synthesis of supported metal catalysts-From the understanding of the well known recipes to new materials[J]. Catal Today, 2015, 246: 46-54.
[7] 林胜达, 唐浩东, 吕兆坡, 刘采来, 岑亚青, 刘化章. 沉淀方法对铜基甲醇合成催化剂前驱体及其性能的影响[J]. 催化学报, 2010, 31(10): 1257-1262.(LIN Sheng-da, TANG Hao-dong, LV Zhao-bo, LIU Cai-lai, CEN Ya-qing, LIU Hua-zhang. Influence of precipitation methods on precursors and properties of Cu-based catalyst for methanol synthesis[J]. Chin J Catal, 2010, 31(10): 1257-1262.)
[8] BALTES C, VUKOJEVI. Correlations between synthesis, precursor, and catalyst structure and activity of a large set of CuO/ZnO/Al2O3 catalysts for methanol synthesis[J]. J Catal, 2008, 258(2): 334-344.
[9] BEHRENS M, ZANDER S, KURR P, JACOBSEN N, SENKER J, KOCH G, RESSLER T, FISCHER R, SCHLOGL R. Performance improvement of nanocatalysts by promoter-induced defects in the support material: Methanol synthesis over Cu/ZnO:Al[J]. J Am Chem Soc, 2013, 135(16): 6061-6068.
[10] 李忠, 郭启海, 张小兵, 郑华艳, 范辉, 谢克昌. 前驱体物相转变对浆态床合成甲醇催化剂活性的影响[J]. 高等学校化学学报, 2009, 30: 2215-2221.(LI Zhong, GUO Qi-hai, ZHANG Xiao-bing, ZHENG Hua-yan, FAN Hui, XIE Ke-chang. Influence of the precursor phase transition on the catalyst activity in slurry methanol synthesis[J]. Chem J Chin Univ, 2009, 30: 2215-2221.)
[11] BEHRENS M, KASATKIN I, KüHL S. Phase-pure Cu,Zn,Al hydrotalcite-like materials as precursors for copper rich Cu/ZnO/Al2O3 catalysts[J]. Chem Mater, 2010, 22(2): 386-397.
[12] BAHMANI M, VASHEGHANI FARAHANI B, SAHEBDELFAR S. Preparation of high performance nano-sized Cu/ZnO/Al2O3 methanol synthesis catalyst via aluminum hydrous oxide sol[J]. Appl Catal A: Gen, 2016, 520: 178-187.
[13] CHU Z, CHEN H, YU Y, WANG Q, FANG D Y. Surfactant-assisted preparation of Cu/ZnO/Al2O3 catalyst for methanol synthesis from syngas[J]. J Mol Catal A: Chem, 2013, 366: 48-53.
[14] 李忠, 张小兵, 郭启海, 刘岩, 郑华艳. 沉淀及老化温度对浆态床合成甲醇铜锌铝催化剂活性及稳定性的影响[J]. 燃料化学学报, 2012, 40(5): 569-575.(LI Zhong, ZHANG Xiao-bing, GUO Qi-hai, LIU Yan, ZHENG Hua-yan. Influence of precipitation and aging temperature on the performance of CuO/ZnO/Al2O3 catalyst for methanol synthesis in slurry reactor[J]. J Fuel Chem Technol, 2012, 40(5): 569-575.)
[15] SCHUMANN J, TARASOV A, THOMAS N, SCHLOGL R, BEHRENS M. Cu,Zn-based catalysts for methanol synthesis: On the effect of calcination conditions and the part of residual carbonates[J]. Appl Catal A: Gen, 2016, 516: 117-126.
[16] ZHANG F, ZHANG Y L, LIU Y, GASEM K, CHEN J Y, CHIANG F G, WANG Y G, FAN M. Synthesis of Cu/Zn/Al/Mg catalysts on methanol production by different precipitation methods[J]. Mol Catal, 2017, 441: 190-198.
[17] MILLAR G J, HOLM I H, UWINS P J R, DRENNAN J. Characterization of precursors to methanol synthesis catalysts Cu/ZnO system[J]. J Chem Soc Faraday Trans, 1998, 94(4): 593-600.
[18] BEMS B, SCHUR M, DASSENOY A, JUNKES H, HEREIN D, SCHLOGL R. Relations between synthesis and microstructural properties of copper/zinc hydroxycarbonates[J]. Chem-Eur J, 2003, 9(9): 2039-2052.
[19] GAO P, LI F, ZHAN H, ZHAO N, XIAO F, WEI W, ZHONG L, WANG H, SUN Y H. Influence of Zr on the performance of Cu/Zn/Al/Zr catalysts via hydrotalcite-like precursors for CO2 hydrogenation to methanol[J]. J Catal, 2013, 298: 51-60.
[20] KüHL S, TARASOV A, ZANDER S, KASATKIN I, BEHRENS M. Cu-based catalyst resulting from a Cu,Zn,Al hydrotalcite-like compound: A microstructural, thermoanalytical, and in-situ XAS study[J]. Chem-Eur J, 2014, 20(13): 3782-3792.
[21] BEHRENS M. Promoting the synthesis of methanol: Understanding the requirements for an industrial catalyst for the conversion of CO2[J]. Angew Chem Int Ed, 2016, 55(48): 14906-14908.Effect of aluminum proportion on the Cu/ZnO/Al2O3 methanol-synthesis catalystZHANG Fan FENG Bo DUAN Xue-lei LI Jing CHEN Jing-yun ZHANG Yu-long SUN Qi 铝元素的添加促进了高温碳酸盐的形成,进而影响到催化剂性能。J Fuel Chem Technol, 2019, 47(3): 329-337 富含介孔Ni/W-USY/Al2O3催化剂的费托蜡加氢裂化性能韩磊黄传峰刘树伟程秋香常方圆