Dimethyl ether is one of the most promising environmentally optimized alternatives to the conventional fossil fuels and an important platform molecule for chemical industry. Catalyst deactivation is one of the most important challenges of the single-step dimethyl ether synthesis from syngas. Because of the lack of direct characterization techniques working under harsh reaction conditions, the information about deactivation mechanisms of bifunctional Cu/ZSM-5 catalysts is rather contradictory. In this paper, a combination of synchrotron-based in-situ time-resolved X-ray diffraction and X-ray absorption spectroscopy operating under high pressure and temperature alongside with the conventional ex-situ characterization uncovered very rapid copper sintering occurring under realistic conditions of direct dimethyl ether synthesis. Copper sintering was strongly affected by the presence of water either produced by the reaction or co-fed to the reactor. No copper oxidation was observed under a wide range of experimental conditions.

二甲醚是传统化石燃料最有前途的环保优化替代品之一，也是化学工业的重要平台分子。从合成气一步合成二甲醚是催化剂失活的最重要挑战之一。由于缺乏在苛刻的反应条件下工作的直接表征技术，因此有关双功能Cu / ZSM-5催化剂失活机理的信息相当矛盾。本文将基于同步加速器的原位时间分辨X射线衍射和X射线吸收光谱技术结合在高压和高温下运行以及常规的非原位表征揭示了在直接合成二甲醚的实际条件下发生的非常快速的铜烧结。铜的烧结受到反应产生的水或共同进料到反应器中的水的存在的强烈影响。在广泛的实验条件下均未观察到铜氧化。