The combination of well-defined acid sites, shape-selective properties and outstanding stability places zeolites among the most practically relevant heterogeneous catalysts. The development of structure–performance descriptors for processes that they catalyse has been a matter of intense debate, both in industry and academia, and the direct conversion of methanol to olefins is a prototypical system in which various catalytic functions contribute to the overall performance. Propylene selectivity and resistance to coking are the two most important parameters in developing new methanol-to-olefin catalysts. Here, we present a systematic investigation on the effect of acidity on the performance of the zeolite ‘ZSM-5’ for the production of propylene. Our results demonstrate that the isolation of Brønsted acid sites is key to the selective formation of propylene. Also, the introduction of Lewis acid sites prevents the formation of coke, hence drastically increasing catalyst lifetime.

明确定义的酸位，形状选择性能和出色的稳定性相结合，使沸石成为最实用的非均相催化剂之一。在工业界和学术界，针对催化过程的结构性能描述的发展一直是争论不休的问题，而甲醇直接转化为烯烃是一个典型的系统，其中各种催化功能都对整体性能有所贡献。丙烯的选择性和抗结焦性是开发新型甲醇制烯烃催化剂的两个最重要的参数。在这里，我们对酸度对生产丙烯的沸石“ ZSM-5”的性能影响进行了系统的研究。我们的结果表明，布朗斯台德酸位点的分离是丙烯选择性形成的关键。而且，路易斯酸位点的引入阻止了焦炭的形成，因此大大延长了催化剂的寿命。