School of Chemistry and Chemical Engineering, Hirano Institute for Materials Innovation, Shanghai Jiao Tong University, Shanghai 200240, China.
Sci Rep. 2013;3:2349. doi: 10.1038/srep02349.
The catalytic purification of automobile exhaust gases (CO, NOx and hydrocarbons) is one of the most practiced conversion processes used to lower the emissions and to reduce the air pollution. Nevertheless, the good performance of exhaust gas purification catalysts often requires the high consumption of noble metals such as platinum. Here we report that the Brønsted acid sites on the external surface of a microporous silicoaluminophosphate (SAPO) act as a promoter for exhaust gas purification, effectively cutting the loading amount of platinum in the catalyst without sacrifice of performance. It is revealed that in the Pt-loaded SAPO-CHA catalyst, there exists a remarkable synergistic effect between the Brønsted acid sites and the Pt nanoparticles, the former helping to adsorb and activate the hydrocarbon molecules for NO reduction during the catalytic process. The thermal stability of SAPO-CHA also makes the composite catalyst stable and reusable without activity decay.
汽车尾气（CO、NOx 和碳氢化合物）的催化净化是应用最广泛的转化过程之一，用于降低排放和减少空气污染。然而，尾气净化催化剂的良好性能通常需要大量消耗贵金属，如铂。在这里，我们报告了微孔硅铝磷酸（SAPO）外表面上的 Brønsted 酸位作为尾气净化的促进剂，有效地减少了催化剂中铂的负载量，而不牺牲其性能。研究表明，在负载铂的 SAPO-CHA 催化剂中，Brønsted 酸位和 Pt 纳米颗粒之间存在显著的协同效应，前者有助于在催化过程中吸附和激活烃类分子以进行 NO 还原。SAPO-CHA 的热稳定性也使复合催化剂稳定且可重复使用，活性没有衰减。
