Cheng Shuai, Meng Tao, Mao Dongsen, Guo Xiaoming, Yu Jun
School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai201418, P. R. China.
ACS Omega. 2022 Oct 31;7(45):41224-41235. doi: 10.1021/acsomega.2c04880. eCollection 2022 Nov 15.
The addition of boron (B) as a promoter to the Ag/SiO 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 catalyst (Ag-B/SiO) was inferior to incipient wetness impregnation introduction of the Ag/SiO catalyst (B/Ag/SiO). Moreover, the effects of B contents (0.5-5 wt %) on the physicochemical properties and catalytic performance of the B/Ag/SiO catalysts were investigated by XRF, N-physisorption, XRD, FTIR, TEM, EDX mapping, H-TPR, NH-TPD, XPS, and catalytic testing. The results indicated that both the catalytic activity and stability of the Ag/SiO catalyst were noticeably enhanced after the introduction of B. The B/Ag/SiO 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.
研究了在用于草酸二甲酯（DMO）选择性加氢制乙醇酸甲酯（MG）的Ag/SiO催化剂中添加硼（B）作为促进剂的情况。对掺入B的制备方法进行比较发现，在Ag/SiO催化剂的氨蒸发沉积沉淀合成过程中添加（Ag-B/SiO）不如初湿浸渍法引入Ag/SiO催化剂（B/Ag/SiO）。此外，通过X射线荧光光谱法（XRF）、N物理吸附、X射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、透射电子显微镜（TEM）、能谱分析（EDX）映射、程序升温还原（H-TPR）、程序升温脱附（NH-TPD）、X射线光电子能谱（XPS）和催化测试，研究了B含量（0.5-5 wt%）对B/Ag/SiO催化剂物理化学性质和催化性能的影响。结果表明，引入B后，Ag/SiO催化剂的催化活性和稳定性均显著提高。含1 wt%B的B/Ag/SiO催化剂表现出最佳的催化性能，DMO转化率为100%，MG选择性为88.3%，这可归因于活性金属的最高分散度以及银与硼物种之间的强相互作用稳定的最小Ag粒径。
