Institute of Surface Chemistry and Catalysis, Ulm University, 89069, Ulm, Germany.
Max-Planck-Institut für Kohlenforschung, 45470, Mülheim an der Ruhr, Germany.
Angew Chem Int Ed Engl. 2017 Aug 1;56(32):9597-9602. doi: 10.1002/anie.201702178. Epub 2017 Jul 6.
Au/Mg(OH) catalysts have been reported to be far more active in the catalytic low-temperature CO oxidation (below 0 °C) than the thoroughly investigated Au/TiO catalysts. Based on kinetic and in situ infrared spectroscopy (DRIFTS) measurements, we demonstrate that the comparatively weak interaction of Au/Mg(OH) with CO formed during the low-temperature reaction is the main reason for the superior catalyst performance. This feature enables rapid product desorption and hence continuous CO oxidation at temperatures well below 0 °C. At these temperatures, Au/TiO also catalyzes CO formation, but does not allow for CO desorption, which results in self-poisoning. At higher temperatures (above 0 °C), however, CO formation is rate-limiting, which results in a much higher activity for Au/TiO under these reaction conditions.
Au/Mg(OH)催化剂在低温 CO 氧化（低于 0°C）催化方面比经过深入研究的 Au/TiO 催化剂活性高得多。基于动力学和原位红外光谱（DRIFTS）测量，我们证明了在低温反应过程中形成的 Au/Mg(OH)与 CO 之间的相对较弱的相互作用是导致催化剂性能优异的主要原因。这一特性使得产物能够快速脱附，从而在远低于 0°C 的温度下实现连续 CO 氧化。在这些温度下，Au/TiO 虽然也能催化 CO 的生成，但不能使 CO 脱附，这导致了自身中毒。然而，在较高温度（高于 0°C）下，CO 的生成是速率限制步骤，因此在这些反应条件下 Au/TiO 的活性要高得多。
