Rational design of hydroxyapatite/graphite-supported bimetallic Cu–M (M = Cu, Fe, Co, Ni) catalysts for enhancing the partial hydrogenation of dimethyl oxalate to methyl glycolate

Abstract

Noble metal-free hydroxyapatite (Ca10(PO4)6(OH)2)/graphite composite supported CuCo catalysts are developed and exhibited outstanding stability and catalytic performance in dimethyl oxalate hydrogenation reaction to methyl glycolate.

Alkaline earth modified activated carbon supported Cu catalysts with enhanced selectivity in the hydrogenation of dimethyl oxalate to methyl glycolate

“…34 It has been shown that the ratio between Cu 0 and Cu + has a great influence on the reaction of Cu-based catalysts in DMO gas-phase hydrogenation. Cheng 35 et al , Wang 36 et al , and Abbas 37,38 et al all concluded that the presence of Cu + is beneficial to improve the stability of the catalyst against MG. In this paper, when the Ca loading is 0.1 wt% and the ratio of Cu + is 0.65 is optimal for the MG selectivity.…”

“…And the reaction pressure is greatly reduced, basically around 2.5–3 MPa. 9–14 Fig. 1 shows the reaction pathway of MG by gas-phase hydrogenation of DMO.…”

“…Most of the currently studied Cu-based catalysts used silica as support, but the silica-supported catalyst was more prone to hydrogenation to ethylene glycol or ethanol during DMO hydrogenation. The MG selectivity was improved on the catalysts of Cu supported on activated carbon (AC), 10 hydroxyapatite–graphite, 11 ZrO 2 –SiO 2 , 12 MgO, 13 and Reduced graphene oxide 14 in DMO hydrogenation. Huang 15 et al found that the MG selectivity reached 99.8% and the yield reached 83% in the DMO hydrogenation to MG after the Cu/SiO 2 catalyst was modified with Na 2 SiO 3 .…”

“…Larger pores could enable the generated MG to be quickly transferred to the outer surface, thus preventing further hydrogenation of MG to generate EG. Similarly, Abbas 11 et al prepared a catalyst with a novel structure using Cu species as the active component, transition metal (Fe, Ni, Co) as the additive, and HAP-G as the support for DMO hydrogenation. The results showed that the selectivity of Cu/HAP-G catalyst to MG can reach 94% at high copper content (20 wt%).…”

“…Wang 12 et al introduced ZrO 2 into silica to increase the disperse of active Cu species, and the electron transfer between Zr and Cu could increase the Cu + content, which improved the hydrogenation stability of the catalysts. Abbas 11 et al introduced ZrO 2 into the supports of hydroxyapatite (HAP) and a composite type of graphite (G). The introduction of Ni increased the dual active center sites on the catalyst surface and also increased the concentration of Cu 0 species, enhancing the mutual synergistic effect between Cu 0 and Cu + .…”