摘要
通过水热法合成盘状ZnO,并在其表面负载Cu得到Cu/盘状ZnO模型催化剂,将不同气氛下(5%CO/Ar、2.5%H_2/2.5%CO/Ar、5%H_2/Ar,分别记为CZ-5CO、CZ-2.5H_2-2.5CO、CZ-5H_2)还原的模型催化剂用于逆水煤气变换反应.对催化剂进行热重分析(TGA)、X射线衍射(XRD)、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)、原位紫外拉曼光谱(in situ UV-Raman)表征.结果表明,不同的还原气氛可得到不同尺寸的Cu颗粒及不同缺陷浓度的Cu-ZnO界面.CO_2程序升温脱附(CO_2-TPD)结果表明,不同的Cu-ZnO界面具有不同的CO_2活化能力.其中CZ-5H_2形成的Cu-ZnO界面对CO_2活化能力最强,表现出最佳的逆水煤气变换反应活性;CZ-5CO具有更多的表面缺陷可能是由于存在Cu_3Zn合金,但Cu-ZnO界面上CO_2的吸附容量降低,导致逆水煤气变换反应活性低;CZ-2.5H_2-2.5CO的活性介于CZ-5H_2与CZ-5CO之间,界面对CO_2的活化量也介于两者之间.
ZnO plate was synthesized by hydrothermal method, and Cu was loaded on the surface of ZnO to obtain Cu/ZnO plate model catalyst. The catalyst was reduced under different atmospheres(5%CO/Ar, 2.5%H_2/2.5%CO/Ar, 5%H_2/Ar, labeled as CZ-5 CO, CZ-2.5 H_2-2.5 CO, CZ-5 H_2, respectively) and then evaluated for the reverse water gas shift reaction. Specifically, the catalysts were characterized by thermogravimetric analysis(TGA), X-ray diffraction(XRD), scanning electron microscopy(SEM), X-ray photoelectron spectroscopy(XPS) and in situ UV-Raman spectroscopy. The results indicate that the treatments under different reducing atmospheres can result in different Cu particle sizes and Cu-ZnO interfaces with different surface defect concentrations. And CO_2 temperature programmed desorption(CO_2-TPD) results show that different Cu-ZnO interfaces possess different CO_2 activation capabilities. The Cu-ZnO interface formed in CZ-5 H_2 has the strongest CO_2 activation ability and exhibits the best reverse water gas shift reaction activity. CZ-5 CO has much more surface defects which may be due to the presence of Cu_3Zn alloy, leading to lower CO_2 adsorption capacity at the Cu-ZnO interface, resulting in low activity for reverse water gas shift reaction. In addition, the activity and the CO_2 activation amount of CZ-2.5 H_2-2.5 CO at the interface are both between those of CZ-5 H_2 and CZ-5 CO.
引文
Ahmad M,Pan C,Zhu J.2010.Investigation of hydrogen storage capabilities of ZnO-based nanostructures [J].The Journal of Physical Chemistry C,114:2560-2565
Aresta M,Dibenedetto A,Angelini A.2014.Catalysis for the valorization of exhaust carbon:from CO2 to chemicals,materials,and fuels.Technological use of CO2 [J].Chemical Reviews,114(3):1709-1742
Bao Y,Huang C,Chen L,et al.2018.Highly efficient Cu/anatase TiO2 {001}-nanosheets catalysts for methanol synthesis from CO2 [J].Journal of Energy Chemistry,27(2):381-388
Behrens M,Studt F,Kasatkin I,et al.2012.The active site of methanol synthesis over Cu/ZnO/Al2O3 industrial catalysts [J].Science,336(6083):893-897
Centi G,Quadrelli E A,Perathoner S.2013.Catalysis for CO2 conversion:a key technology for rapid introduction of renewable energy in the value chain of chemical industries [J].Energy & Environmental Science,6(6):1711-1731
Chen D,Wang Z,Ren T,et al.2014.Influence of defects on the photocatalytic activity of ZnO [J].The Journal of Physical Chemistry C,118(28):15300-15307
Chinchen G C,Waugh K C,Whan D A.1986.The activity and state of the copper surface in methanol synthesis catalysts [J].Applied Catalysis,25(1/2):101-107
Derrouiche S,Lauron-Pernot H,Louis C.2012.Synthesis and treatment parameters for controlling metal particle size and composition in Cu/ZnO materials-first evidence of Cu3Zn alloy formation [J].Chemistry of Matericals,24:2282-2291
Dong X,Li F,Zhao N,et al.2017.A study on the order of calcination and liquid reduction over Cu-based catalyst for synthesis of methanol from CO2/H2 [J].Catalysis Letters,147(5):1235-1242
Dong X,Li F,Zhao N,et al.2016.CO2 hydrogenation to methanol over Cu/ZnO/ZrO2 catalysts prepared by precipitation-reduction method [J].Applied Catalysis B:Environmental,191:8-17
丁艳敏,李彩亭,曾光明,等.2009.Mn/Fe-Mn改性HZSM-5在NH3-SCR中的催化性能 [J].环境科学学报,29(12):2572-2577
Figueiredo R T,Santos M S,Andrade H M C,et al.2011.Effect of alkali cations on the CuZnOAl2O3 low temperature water gas-shift catalyst [J].Catalysis Today,172(1):166-170
Galván C á,Schumann J,Behrens M,et al.2016.Reverse water-gas shift reaction at the Cu/ZnO interface:Influence of the Cu/Zn ratio on structure-activity correlations [J].Applied Catalysis B:Environmental,195:104-111
Goeppert A,Czaun M,Jones J P,et al.2014.Recycling of carbon dioxide to methanol and derived products-closing the loop [J].Chemical Society Reviews,43(23):7995-8048
Grunwaldt J D,Molenbroek A M,Tops?e N Y,et al.2000.In situ investigations of structural changes in Cu/ZnO catalysts [J].Journal of Catalysis,194(2):452-460
Halder A,Kilianová M,Yang B,et al.2018.Highly efficient Cu-decorated iron oxide nanocatalyst for low pressure CO2 conversion [J].Applied Catalysis B:Environmental,225:128-138
Hansen P L,Wagner J B,Helveg S,et al.2002.Atom-resolved imaging of dynamic shape changes in supported copper nanocrystals [J].Science,295(15):2053-2055
Jia J,Qian C,Dong Y,et al.2017.Heterogeneous catalytic hydrogenation of CO2 by metal oxides:defect engineering-perfecting imperfection [J].Chemical Society Reviews,46(15):4631-4644
Jones S D,Hagelin-Weaver H E.2009.Steam reforming of methanol over CeO2- and ZrO2-promoted Cu-ZnO catalysts supported on nanoparticle Al2O3 [J].Applied Catalysis B:Environmental,90(1/2):195-204
Kattel S,Ramírez P J,Chen J G,et al.2017.Active sites for CO2 hydrogenation to methanol on Cu/ZnO catalysts [J].Science,355(6331):1296-1299
Kuld S,Conradsen C,Moses P G,et al.2014.Quantification of zinc atoms in a surface alloy on copper in an industrial-type methanol synthesis catalyst [J].Angewandta Chemie International Edition,53(23):5941-5945
Kuld S,Thorhauge M,Falsig H,et al.2016.Quantifying the promotion of Cu catalysts by ZnO for methanol synthesis [J].Science,352(6288):969-974
Li G R,Hu T,Pan G L,et al.2008.Morphology-function relationship of ZnO:polar planes,oxygen vacancies,and activity [J].The Journal of Physical Chemistry C,112:11859-11864
Liao F,Huang Y,Ge J,et al.2011.Morphology-dependent interactions of ZnO with Cu nanoparticles at the materials' interface in selective hydrogenation of CO2 to CH3OH [J].Angewandta Chemie International Edition,50(9):2162-2165
Lunkenbein T,Schumann J,Behrens M,et al.2015.Formation of a ZnO overlayer in industrial Cu/ZnO/Al2O3 catalysts induced by strong metal-support interactions [J].Angewandta Chemie International Edition,54(15):4544-4548
Lv J,Sun Y,Cao L,et al.2015.Effect of reaction temperature on surface morphology and photoelectric properties of ZnO grown by hydrothermal method in mixed solvent [J].J Mater Sci:Mater Electron,26(7):5518-5523
李淑君,彭若斯,孙西勃,等.2018.Pt/CeO2催化氧化甲苯反应机制研究 [J].环境科学学报,38(4):1426-1436
Natesakhawat S,Lekse J W,Baltrus J P,et al.2012.Active sites and structure-activity relationships of copper-based catalysts for carbon dioxide hydrogenation to methanol [J].ACS Catalysis,2(8):1667-1676
Olah G A.2013.Towards oil independence through renewable methanol chemistry [J].Angewandta Chemie International Edition,52(1):104-107
Olah G A.2005.Beyond oil and gas:the methanol economy [J].Angewandta Chemie International Edition,44(18):2636-2639
Perathoner S,Centi G.2014.CO2 recycling:a key strategy to introduce green energy in the chemical production chain [J].ChemSusChem,7:1274-1282
Porosoff M D,Yan B,Chen J G.2016.Catalytic reduction of CO2 by H2 for synthesis of CO,methanol and hydrocarbons:challenges and opportunities [J].Energy & Environmental Science,9(1):62-73
Ren H,Xu C H,Zhao H Y,et al.2015.Methanol synthesis from CO2 hydrogenation over Cu/γ-Al2O3 catalysts modified by ZnO,ZrO2 and MgO [J].Journal of Industrial Engineering Chemistry,28:■.Raman study of structural disorder in ZnO nanopowders [J].Journal of Raman Spectroscopy,41:914-921
王冠男,陈礼敏,郭园园,等.2014.铬助剂对Cu/ZrO2/CNTs-NH2催化剂催化CO2加氢合成甲醇性能的影响[J].物理化学学报,30(5):923-931
Yang X,Chen H,Meng Q,et al.2017.Insights into influence of nanoparticle size and metal-support interactions of Cu/ZnO catalysts on activity for furfural hydrogenation [J].Catalysis Science & Technology,7(23):5625-5634