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用共沉淀法制备一系列六铝酸盐催化剂样品(LaMeAl11O19,Me=Mn、Fe、Co、Ni、Ni、Ce),采用X-射线衍射(X-ray diffraction,XRD)、比表面积测试法(Brunauer-Emmett-Teller,BET)和X-射线光电子能谱(X-rayphotoelectron spectrometry,XPS)等方法对样品结构进行表征,并通过生物质气化气中可燃气体成分(CH4/CO/H2)的模拟燃烧试验,考察不同过渡金属离子取代对催化剂结构特征及催化燃烧活性的影响。利用原位红外(in-situ DRIFT)方法研究了气体在催化剂表面反应的机制。结果表明,焙烧后催化剂形成具有相同的MP结构、但化学组分不同的六铝酸盐,且具有较大的比表面积。LaMeAl11O19催化剂对模拟生物质气化气中可燃成分燃烧均具有一定的催化活性,添加Mn离子时催化剂对甲烷的催化燃烧活性最好。各可燃气体起燃温度自低至高为CO、H2、CH4。150℃时CO已在催化剂表面发生吸附,250℃出现气相CO2的吸附峰,同时检测到反应气中H2被催化剂内部晶格氧所氧化生成的水分子吸附峰。气相CH4的吸附峰在反应开始(150℃)时就已形成,其强度和位置不随温度和时间变化。
A series of hexaaluminate catalyst samples (LaMeAl11O19, Me = Mn, Fe, Co, Ni, Ni and Ce) were prepared by coprecipitation method and characterized by XRD and BET Brunauer-Emmett-Teller (BET) and X-ray photoelectron spectroscopy (XPS) were used to characterize the structure of the sample and to pass through the combustible gas composition (CH4 / CO / H2) Simulated combustion tests were conducted to investigate the effects of different transition metal ion substitutions on the catalyst structure and catalytic combustion activity. In-situ IR (in-situ DRIFT) method was used to study the mechanism of gas reaction on the catalyst surface. The results show that after calcination, the catalyst forms hexaaluminate with the same MP structure but different chemical components and has a larger specific surface area. LaMeAl11O19 catalyst has certain catalytic activity for combustibility of combustible components in simulated biomass gasification gas, and the catalyst has the best catalytic combustion activity on methane when Mn ions are added. CO, H2, CH4.150 ℃ CO has been adsorbed on the catalyst surface, 250 ℃ gas-phase CO2 adsorption peak appeared at the same time detected in the reaction gas H2 by the catalyst inside the lattice oxygen Oxidation of water molecules generated adsorption peak. Gas-phase CH4 adsorption peak at the beginning of the reaction (150 ℃) has formed, its intensity and location does not change with temperature and time.