Using synchrotron X-ray powder diffraction-mass spectrometry in combination with theoretical calculations, we probed the structural changes of adsorbed methanol species in H-ZSM-5 for the first time during catalytic conversion of methanol. Preliminary experimental and computational findings suggested that associative mechanism was the dominant reaction pathway in the early stage of the reaction at 200 °C. Also, we observed a minor contribution from dissociative mechanism of the adsorbed methoxy intermediate species, CH₃-O_z (where O_z is a framework oxygen atom), at Brønsted acid sites. It led to methoxy accumulation during the late stage of the reaction, which was postulated to be the initial step that produced ‘hydrocarbon pool’ and ‘coke’ through the formation of CC bonds.

使用同步加速器X射线粉末衍射质谱法和理论计算相结合，我们首次探查了甲醇催化转化过程中H-ZSM-5中吸附的甲醇物种的结构变化。初步的实验和计算结果表明，在200°C反应的早期，缔合机理是主要的反应途径。此外，我们观察到吸附的甲氧基中间物质CH ₃ -O _z（其中O _z是一个框架氧原子），位于布朗斯台德酸性位置。它导致了反应后期甲氧基的积累，这被认为是通过形成C C键产生“碳氢化合物库”和“焦炭”的第一步。