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用尿素均匀沉淀法制备了NiO-ZrxCe1-xO2复合氧化物,并用XRD、TPR、TPD和原位红外对其晶相结构、NiO与载体的相互作用、催化剂的表面酸碱性能和NiO-ZrxCe1-xO2对CO2和CH3OH吸附性等进行了表征。结果表明,Zr0.7Ce0.3O2形成固溶体,且表面具有酸性中心和碱性中心,除NiO-Zr0.1Ce0.9O2样品外,各催化剂均能使CH3OH发生解离吸附,而CO2在各催化剂表面发生了单齿吸附,在金属位上发生了线式吸附和剪式吸附,在金属位和酸性位的协同作用下发生了卧式吸附。NiO-Zr0.7Ce0.3O2催化剂在CO2和CH3OH常压合成碳酸二甲酯(DMC)反应中表现出较好的催化活性和选择性。
The NiO-ZrxCe1-xO2 composite oxide was prepared by uniform precipitation of urea. The crystal structure of NiO-ZrxCe1-xO2 composite was characterized by XRD, TPR, TPD and in situ IR. The interaction between NiO and support, the surface acid- xO2 adsorption of CO2 and CH3OH were characterized. The results show that Zr0.7Ce0.3O2 forms a solid solution and has acidic and basic centers on the surface. Except for NiO-Zr0.1Ce0.9O2 samples, all the catalysts can dissociate CH3OH and CO2 on the surface of each catalyst The monodentate adsorption, linear adsorption and scission adsorption occurred in the metal position, and the horizontal adsorption occurred under the synergetic effect of metal sites and acidic sites. The NiO-Zr0.7Ce0.3O2 catalyst shows good catalytic activity and selectivity in the reaction of CO2 and CH3OH at atmospheric pressure to produce dimethyl carbonate (DMC).