a catalyst comprising a high surface area porous silica and processes for preparing a catalyst, for making ethylenically unsaturated acids or esters thereof and for making methyl methacrylate

摘要

A catalyst comprising a high surface area porous silica, processes for preparing a catalyst, for making ethylenically unsaturated acids or esters thereof and for making methyl methacrylate, and use of boron as a stabilizer for a catalyst. the production of ethylenically unsaturated acids or esters by the catalytic reaction of an alkanoic acid or ester, especially methyl propionate, with formaldehyde and a catalyst for this purpose, wherein the catalyst comprises a high surface area porous silica containing from 1 to 10% by weight of an alkali metal, especially cesium (expressed as metal) and having at least one modifying element selected from boron, magnesium, aluminum, zirconium and hafnium dispersed in the pores of said silica in such quantity that the catalyst contains a total of 0.25 to 2 gram atoms of primary modifying element per 100 moles of silica.