孔结构对低压合成气制甲醇选择性的影响Effects of Pore Structure on Methanol Selectivity in Carbon Monoxide Hydrogenation
柳艳炉,蒋新,卢建刚
摘要(Abstract)：
采用共沉淀法在不同压片压力和黏结剂种类条件下制备Cu/Zn O/Al2O3催化剂,通过TEM、BET等表征手段考察了催化剂微结构以及催化特性的变化。研究表明,压片压力增大,内扩散阻力增大,导致CO转化率降低,而甲醇选择性增大。通过分析反应机理,比较反应条件下CO和H2分子运动平均自由程,得出孔结构变化对两种反应气体扩散影响不同。孔结构变化使孔道内活性中心表面H2相对浓度下降后,各反应路径受到的影响不同,反应速率下降的比例不同,从而导致反应的选择性改变。随后不同分子量黏结剂的实验验证了这一判断。
关键词(KeyWords)： 孔结构;内扩散;甲醇选择性;铜基催化剂;合成气
基金项目(Foundation): 国家自然科学基金(21276223);; 国家863高技术研究发展计划(2010AA064905);; 浙江省重点科技创新团队计划(2009R50020)
作者(Author): 柳艳炉,蒋新,卢建刚
参考文献(References)：
- [1]CI Zhi-min(慈志敏).Study on Cu-based catalysts for methanol synthesis from CO hydrogenation(一氧化碳加氢合成甲醇用铜基催化剂的研究)[D].Chengdu(成都):Sichuan University(四川大学),2006.
- [2]Waugh K C.Methanol synthesis[J].Catal Lett,2012,142(10):1153-1166.
- [3]LIU Guo-ji(刘国际),YAO Pei-fang(姚佩芳),ZHU Bing-chen(朱炳辰).Effects of pore structures on global reaction rates of methanol synthesis on Cu-based catalyst(孔结构对铜基甲醇合成催化剂宏观反应速率的影响)[J].Journal of Fuel Chemistry and Technology(燃料化学学报),1994,22(2):183-188.
- [4]CHEN Cong-biao(陈从标),CHEN Jian-gang(陈建刚),FANG Ke-gong(房克功),et al.Effect of intraparticle diffusion on F-T synthesis(内扩散行为对F-T合成反应过程影响的研究)[J].Journal of Fuel Chemistry and Technology(燃料化学学报),2010,38(5):588-593.
- [5]Graaf G H,Scholtens H,Stamhuis E J,et al.Intra-particle diffusion limitations in low-pressure methanol synthesis[J].Chem Eng Sci,1990.45(4):773-784.
- [6]Szeifert F,Arva P,Nagy D.Effects of pore diffusion on the synthesis of methanol[J].Chem Eng Comm,1989,76(1):157-167.
- [7]TANG Qian-lin,HONG Qi-jun,LIU Zhi-pan.CO2 fixation into methanol at Cu/Zr O2 interface from first principles kinetic Monte Carlo[J].J Catal,2009,263(1):114-122.
- [8]Edward M C.Kinetic model for alcohol synthesis over a promoted Cu/Zn O/Cr2O3 catalyst[J].Ind Eng Chem Res,1992,31(3):792-803.
- [9]Grabow L C,Mavrikakis M.Mechanism of methanol synthesis on Cu through CO2 and CO hydrogenation[J].ACS Catal,2011,1(4):365-384.
- [10]Youngs T G A,Haq S,Bowker M.Formic acid adsorption and oxidation on Cu(110)[J].Sur Sci,2008,602(10):1775-1782.
- [11]YANG Jia,QI Yan-ying,ZHU Jun,et al.Reaction mechanism of CO activation and methane formation on Co Fischer-Tropsch catalyst:A combined DFT,transient,and steady-state kinetic modeling[J].J Catal,2013,308(12):37-49.
- [12]YANG Jia,CHEN De,Holmen Anders.Understanding the kinetics and Re promotion of carbon nanotube supported cobalt catalysts by SSITKA[J].Catal Today,2012,186(1):99-108.
- [13]Bowker M,Hadden R A,Waugh K C,et al.The mechanism of methanol synthesis on copper/zinc oxide/alumina catalysts[J].J Catal,1988,109(2):263-273.
- [14]Enrico E O,Johanna M W,Wokaun A.Methanol synthesis pathway over Cu/Zr O2 catalysts:A time-resolved DRIFT 13C-labelling experiment[J].Cata Lett,1998,54(1-2):41-48.
- [15]Sahibzada M,Metcalfe I S,Chadwick D.Methanol synthesis from CO/CO2/H2 over Cu/Zn O/Al2O3 at differential and finite conversions[J].J Catal,1998,174(2):111-118.
- [16]Gokhale Amit A,Dumesic James A,Mavrikakis Manos.On the mechanism of low-temperature water gas shift reaction on copper[J].J AM Chem Soc,2008,130(4):1402-1414.
- [17]HU Da-cheng,GAO Jia-jia,PING Yuan,et al.Enhanced investigation of CO methanation over Ni/Al2O3 catalysts for synthetic natural gas production[J].Ind Eng Chem Res,2012,51(13):4875-4886.
- [18]Alstrup I.On the kinetics of CO methanation on nickel surfaces[J].J Catal,1995,151(1):216-225.
- [19]Egbebi Adefemi,Spivey James J.Effect of H2/CO ratio and temperature on methane selectivity in the synthesis of ethanol on Rh-based catalysts[J].Catalysis Communications,2008,9(14):2308-2311.