Selective Hydrogenation of Dimethyl Oxalate to Methyl Glycolate over Boron-Modified Ag/SiO(2) Catalysts

[Image: see text] The addition of boron (B) as a promoter to the Ag/SiO(2) catalyst for the selective hydrogenation of dimethyl oxalate (DMO) to methyl glycolate (MG) was investigated. A comparison of the preparation method for incorporation of B found that the addition during the ammonia evaporation deposition–precipitation synthesis of the Ag/SiO(2) catalyst (Ag–B/SiO(2)) was inferior to incipient wetness impregnation introduction of the Ag/SiO(2) catalyst (B/Ag/SiO(2)). Moreover, the effects of B contents (0.5–5 wt %) on the physicochemical properties and catalytic performance of the B/Ag/SiO(2) catalysts were investigated by XRF, N(2)-physisorption, XRD, FTIR, TEM, EDX mapping, H(2)-TPR, NH(3)-TPD, XPS, and catalytic testing. The results indicated that both the catalytic activity and stability of the Ag/SiO(2) catalyst were noticeably enhanced after the introduction of B. The B/Ag/SiO(2) catalyst with 1 wt % B showed the best catalytic performance of 100% DMO conversion and 88.3% MG selectivity, which could be attributed to the highest dispersion of the active metal and the smallest Ag particle size stabilized by the strong interaction between silver and boron species.