二氧化碳逆水煤气变换催化剂制备与性能

CO_2由于热力学稳定性和动力学惰性,难以高效活化。采用并流沉淀法制备锆酸钡(BaZrO_3)催化剂并用于逆水煤气变换反应,结合物化表征和性能评价考察离子掺杂对催化活性、催化剂结构和还原性能的影响以及水热处理对催化剂结构和性能的影响。结果表明,过渡金属离子掺杂BaZrO_3催化剂产生晶格氧空位,提高CO_2转化率,以Mn离子掺杂的催化剂性能最好。晶格掺杂不会改变催化剂晶相结构,但增强晶格氧迁移能力,促进催化剂容易还原,进而显著提高逆变换催化活性。催化剂经水热处理可消除游离杂相,产物选择性提高至99.4%。优化条件下,Mn掺杂BaZrO_3催化剂上CO_2转化率大于48%,CO选择性大于99%,催化剂稳定性好,具有良好的应用前景。

Preparation and activity of the reverse water gas shift catalyst for CO2 conversion

Carbon dioxide is difficult to activate because of its thermodynamic stability and kinetic inertia.BaZrO₃ perovskite catalyst was prepared by co-precipitation method and used in reverse water gas shift reaction(RWGS).The effects of ion doping on the catalytic activity,catalyst structure,reduction and hydrothermal treatment on the structure and properties of the catalyst were investigated by physicochemical characterization and performance evaluation.The results showed that lattice oxygen vacancies were produced in BaZrO₃ catalyst with metal ion doping,which significantly improved the conversion of CO₂,especially Mn ion doping.The crystal structure of the doped catalyst would not be changed,and the reductive activity of the catalyst was improved,the mobility of lattice oxygen was enhanced,and the catalytic activity for RWGS was enhanced.After hydrothermal treatment,the impurities could be removed and the selectivity of the product increased to 99.4%.The conversion of CO₂ over Mn doped BaZrO₃ catalyst was more than 48%,and CO selectivity was more than 99%.The catalyst has good stability and industrial application future.