面向CO2加氢应用的反应温度匹配型N-CeO2/SAPO-34双功能催化剂制备及性能研究

国际社会广泛关注CO2减排。利用CO2转化为甲醇和低碳烯烃，既可实现CO2资源化，又可减排CO2，具有重要战略意义。但高性能催化剂缺乏仍是CO2转化面临的巨大挑战。在CO2加氢制甲醇用催化剂探索中，申请人首次发现N掺杂CeO2（N-CeO2）具有非常好的甲醇选择性，反应温度达700K时，甲醇选择性仍保持在20%。基于此，本项目提出以N-CeO2和SAPO-34为基础构建反应温度匹配型双功能催化剂新体系，以实现CO2加氢直接高效合成低碳烯烃为目标。探索N-CeO2催化CO2加氢的活化机制及在高温条件下（673K以上）抑制逆水汽反应机制；探索SAPO-34介/微孔道结构/表面性质与加压H2气氛下催化甲醇制低碳烯烃性能关系；构建N-CeO2与SAPO-34复合双功能催化剂，揭示CO2加氢与生成低碳烯烃反应耦合机制，优化催化性能并探索其应用前景，为CO2转化新工艺开发提供理论支撑。

The CO2 emission control have been receiving increasingly attention worldwide. Conversion of CO2 into methanol and lower olefins can achieve not only the utilization of CO2 resource but also the CO2 emission control, which shows the strategic significance. However, it is still a challenge for the activation and high selective conversion of CO2. In our quest for a suitable catalyst for CO2 hydrogenation into methanol, N doped CeO2 (N-CeO2)showed excellent catalytic activity and selectivity. The methanol selectivity was up to 20% even at the 700K. Therefore, we proposed the design of a bifunctional catalyst consisted of N-CeO2 for methanol synthesis and SAPO-34 for carbon-carbon coupling, which was expected to achieve the direct conversion of CO2 and H2 into lower olefins. During the project implement, the activation mechanism of CO2 and H2 on N-CeO2 will be elucidated, the mechanism of reverse water gas shift reaction suppression on N-CeO2 at high temperature (not lower than 673K) will be also investigated, the optimized synthesis of N-CeO2 based catalysts with high performance for CO2 hydrogenation into methanol will be proposed, the optimized synthesis of SAPO-34 with high performance for methanol to lower olefins in high pressure H2 will be also proposed, the N-CeO2/SAPO-34 based bifunctional catalyst will be prepared and the reaction coupling mechanism of methanol synthesis and methanol-to-lower olefins will be carefully investigated. Finally, the successful design of N-CeO2/SAPO-34 based bifunctional catalyst with high performance for CO2 and H2 direct conversion into lower olefins is highly expected.