文献类型：期刊文献

英文题名：Synergy of Lewis and BrOnsted acid sites for polyoxymethylene dimethyl ether synthesis from methanol and formaldehyde solution over Zr4+ modified sulfonated resin

作者：Li, Xiangjun[1];Cao, Jiancheng[1];Nawaz, Muhammad Asif[1];Liu, Dianhua[1]

机构：[1]East China Univ Sci & Technol, State Key Lab Chem Engn, Shanghai 200237, Peoples R China

年份：2021

卷号：289

外文期刊名：FUEL

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000612061700004)】；

基金：This work was financially supported by National Key Research and Development Program of China (No. 2018YFB0604804).

语种：英文

外文关键词：Polyoxymethylene dimethyl ethers; Acidic sulfonated resin; Zirconium modification; Lewis acid sites; Synergistic catalysis

摘要：Polyoxymethylene dimethyl ether (PODEn) is a clean, effective and promising diesel additive. In this work, acidic sulfonated resin modified by zirconium (Zr4+-SR), which possess both Lewis and BrOnsted acid sites, was employed to catalyze the synthesis of PODEn from methanol (MeOH) and formaldehyde (FA) solution. The catalysts were investigated by various characterization methods including SEM, BET, XPS, FT-IR, NH3-TPD, Pyridine FT-IR, TG-MS and ICP-OES. It was found that the introduction of Zr4+ into cationic exchange resin formed the Lewis acid sites and improvement of the catalytic performance in PODEn synthesis from methanol and formaldehyde solution was attributed to the synergistic effect of Lewis and BrOnsted acid sites. With the increase of zirconium loading, the amount of Lewis acid sites and weak acidity of the Zr4+-SR catalyst increased gradually, and the catalytic activity of the catalysts for the PODEn synthesis reaction exhibited a trend of increasing first and then decreasing. In the methanol and formaldehyde solution, BrOnsted acid sites were active for the acetalization of hemiformal and methanol, while Lewis acid sites were conducive to the activation of the methylene glycol. A possible reaction route for the PODEn synthesis from methanol and formaldehyde solution was proposed. 61.1% methanol conversion, 98.7% PODE1-6 and 22.4% PODE3-6 selectivity were achieved under optimal reaction conditions. The reusability investigation of the Zr4+-SR catalyst showed a stable catalytic activity for the synthesis of PODEn from methanol and formaldehyde solution and revealed that the decrease of catalyst activity was attributed to the partial loss of the zirconium.