P-intensified NiCo alloy as robust catalyst for selective hydrogenolysis of dimethyl oxalate

Diester hydrogenolysis is usually a stepwise process to synthesize a variety of value-added commodity oxygenates. As a classic diester compound, dimethyl oxalate (DMO) can be selectively hydrogenolyzed into methyl glycolate (MG), a key monomer to prepare emerging biodegradable polyglycolic acid (PGA). By far, the industrial-scale process is yet suffering from unsatisfied MG selectivity, poor catalyst stability and high catalyst cost with using precious metals. Herein, we report a valid practice by applying P-intensified NiCo alloy for selective hydrogenolysis of DMO to MG. The reaction achieves DMO conversion and MG selectivity as 97% and 90%, respectively, during a 504-hour continuous operation at mild conditions (180℃, 1.5 MPa). Leveraging the synergetic effects of P-NiCo interaction and Ni-Co interaction, a slight content of phosphorus doping could effectively result in robust capability/capacity of H adsorption, enhanced strength of DMO adsorption and facile MG desorption via simultaneously establishing the highly active Ni site and Co site with electron-rich properties for both metals. This work is expected to offer new visions into the rational design of robust bimetallic catalyst with using non-precious metals for not only low-cost and high efficiency but also less-energy-input hydrogenolysis process.