Structural evolution of the CuO catalyst modified with ZnO, Sn, and P promoters in the Rochow-Müller reaction

Promoters such as ZnO, Sn, and P are widely used in Cu-based catalysts for the Rochow-Müller reaction, which dominates the manufacture of organosilane monomers in the chemical industry. However, the effect of these promoters on the Cu-based catalyst structure is still unclear. In this work, we prepared a series of quartz sand (qs) supported CuO catalysts modified with ZnO, Sn, and P promoters through simple ball milling followed by calcination in air. We found that introducing these promoters can enhance the MeCl adsorption on the CuO surface, accelerating the transformation of CuO to Cu2O, then to Cu, further to CuCl, and finally to the active Cu3Si phase, leading to the improved catalytic properties with a higher dimethyldichlorosilane selectivity and Si conversion compared to the pure CuO catalyst. This work first deciphers the structural evolution of the CuO catalyst with and without ZnO, Sn, and P promoters during the Rochow-Müller reaction, which would help understand the reaction mechanism and design more efficient catalysts.