研究了不同载体负载的Au催化剂催化丙三醇水相选择性氧化制丙醇二酸.与Au/CeO2, Au/AC, Au/REY和Au/NaY催化剂相比, Au/HY上获得了高收率的丙醇二酸.在60℃和0.3 MPa氧气压力下,丙三醇转化率达98%,丙醇二酸收率为80%.表征结果表明,小尺寸的Au纳米颗粒对生成丙醇二酸有明显促进作用;反应过程中丙三醇先被催化氧化生成甘油酸,再被进一步氧化生成丙醇二酸.
Gold nanoclusters or nanoparticles on various supports (CeO2, activated carbon, HY, REY, and NaY) were investigated for glycerol oxidation in the aqueous phase under mild conditions. Compared with other catalysts, Au/HY showed remarkable catalytic performance in forming dicarboxylic acid (tartronic acid) over the monocarboxylic acid (glyceric acid) or the C-C cleavage product (oxalic acid). Au/HY achieved 98% conversion of glycerol and 80% yield oftartronic acid at 60 ℃ under 0.3 MPa 02. Further characterization showed that the small size of Au clusters is the key factor for the high oxidation performance. In situ Fourier transform infrared spectroscopy revealed that glycerol was first transformed to glyceric acid, and then Rlyceric acid was directly oxidized to tartronic acid.