Neighboring Cu toward Mn site in confined mesopore to trigger strong interplay for boosting catalytic epoxidation of styrene

Abstract

Herein, we report an efficient controlled approach to reach the synergetic neighboring dual-metal active sites in the confined mesopore of silica. In this approach, Mn-bearing mesoporous molecular sieve was designed in advance via a metal-assisted in-situ assembly route and further employed as a starting carrier to accommodate more extraneous Cu by impregnation. Controlling copper loading (Cu/Mn = 0.2, 0.4, and 0.6), comparative catalysts were attained and precisely characterized by key physicochemical methods. Impressively, in-situ formed highly-dispersed MnOx covered on the mesopore become the prerequisite for producing interplayed active species with neighboring dual Cu-Mn sites. Catalytic results concerning styrene epoxidation together with DRIFTS experiments and calculated bond energy variation in expected reaction intermediates demonstrated the existed synergy derived from formed neighboring Cu-Mn species via weakening and reinforcing appointed chemical bonds in intermediates. This study provides the foreseeable possibility for attaining universal synergetic catalysts in industrial heterogeneous catalysis.