Cerium(IV) Sulfate as a Cocatalyst for Promoting the Direct Epoxidation of Propylene by Ruthenium Porphyrin with Molecular Oxygen

Abstract

The direct epoxidation of propylene to propylene oxide (PO) using molecular oxygen is difficult to achieve. Liquid-phase aerobic propylene epoxidation has been achieved using metalloporphyrin catalysts, but the efficiency was poor. Herein, the direct aerobic epoxidation of propylene was accomplished using ruthenium porphyrin with Ce(SO 4 ) 2 as a cocatalyst. The propylene conversion and PO selectivity were 33.7% and 82.3%, respectively. The efficiency was approximately 2 times higher than RuTPP (ruthenium mesotetraphenylporphyrin) alone and more than 3 times higher than Ce(SO 4 ) 2 alone. Ce(IV) promoted the formation of allyl radicals and promoted the oxidative cleavage of the CC bond of propylene.

Highly efficient and robust aerobic co-oxidation of olefins and aldehydes over CoOx dispersed within hierarchical silicalite-1 zeolites

“…[10][11][12][13][14] In the past several decades, both homogeneous and heterogeneous co-oxidation catalysts based on various transition metal elements, such as Mn, Fe, Co, Ni, Cu and Ru, have been widely reported in the literature. [15][16][17][18][19][20][21][22] Yet, homogeneous catalysts are difficult to be separated and reused, while the rational design and construction of heterogeneous catalysts with high distribution and thermal stability of transition metal species at the same time is still a big challenge, which needs profound understanding at the atomic scale. Notably, among various solid catalysts, metal nanoparticle loaded catalysts with a narrow size distribution show superior catalytic application potential in co-oxidation reactions.…”