Pt基双组分催化体系的构建及脱氢性能研究

Adding a second component can often significantly improve the performance of catalysts. Therefore, the widely application of bi-component catalysts is very important to solve the current energy and environmental problems. The fundamental understanding of structure-performance correlation of bi-component catalysts is one of the core scientific issues in catalysis, and also helps the development of efficient bi-component catalysts. In this project, we will study the surface structure and the performance of Pt-based bi-component catalytic systems from surface science investigation to real supported nanoparticles. We will mainly focus on the controllable construction of Pt-Sn and Pt-3d transitional metal bi-component catalytic systems. Utilizing propane as probe molecule, the adsorption behavior and dehydrogenation processes of propane will be intensively studied on various Pt-Sn bi-component model surfaces and Pt-skin surface with subsurface 3d transitional metal. With the combination of theoretical calculations, the structure-performance correlation of Pt-based bi-component catalytic systems and the dehydrogenation mechanism will be further elucidated. The results of this project is of great important for the development of the fundamental knowledge of bi-component catalysis and subsurface metal catalysis, and will also provide guideline and foundation for the rational design of high-efficient and low-cost dehydrogenation catalysts.

添加第二组分通常能够显著提高催化剂的反应性能，因此双组分催化剂的推广应用对于解决当前严峻的能源与环境问题具有重要的意义。理解双组分催化剂的结构与反应性能之间的关系（构效关系）是目前催化研究中的核心科学问题之一，也是改进双组分催化剂性能的基础。本申请项目拟采用模型催化体系研究与负载型纳米粒子催化剂研究相结合的方式，探索Pt基双（多）组分催化剂的构建，主要是Pt-Sn、Pt-3d过渡金属等体系。以丙烷等低碳烷烃为探针分子，系统研究不同表面上丙烷分子的吸附特征及脱氢反应过程。明确次表层3d过渡金属的引入对表面结构和反应性能的影响。结合密度泛函理论深入认识Pt基双组分催化体系的结构与反应性能的之间的关联，阐明反应机理。本研究课题对于进一步理解和推动双组分催化理论、认识次表层催化的调变规律具有重要的意义，并将为科学制备高性能Pt基脱氢催化剂、减少贵金属催化剂用量等方面提供基础。

近年来国内丙烯需求量增长迅速，丙烷催化脱氢作为一条富有竞争力的生产丙烯的工艺路线，受到了越来越多的关注。这其中的关键是制备高性能的催化剂。但相关技术被美国和德国等少数国家长期垄断，我国现有的13套“丙烷脱氢法”丙烯生产线均从国外高价引进，催化剂也完全依赖进口，中国丙烯工业形成了被西方发达国家“卡脖子”的被动局面。基于此，研究工作围绕“精准设计与构建脱氢催化剂表界面局域原子和电子结构”这一核心科学问题，开展Pt基脱氢催化剂结构构建与催化特性调变研究。主要取得以下研究成果：（1）在Pt基催化剂中，利用表面下的次表层元素、表面中的单原子合金和有序金属间合金等调变Pt表面原子和电子结构，有效增强Pt催化丙烷脱氢等反应性能；（2）在氧化物催化剂体系，从原子和电子层面阐明氧化物表面羟基和氧空位等缺陷位对催化剂结构和催化特性的调变作用，利用缺陷位调变催化剂电子结构，并增强催化脱氢反应性能。相关成果发表在Science Advances、ACS Catalysis、Applied Catalysis B: Environmental、Chemical Science和Chemical Society Reviews等期刊，并申请2项中国专利和2项PCT专利。