Catalyst for producing alpha, beta-ethylenically unsaturated aliphatic

Abstract

A particulate catalyst, especially suitable for condensation of an alpha, beta-ethylenically unsaturated monocarboxylic acid with formaldehyde, is disclosed. The catalyst comprises a catalyst support constituted by porous silica gel, and cesium ions in the +1 oxidation state on the catalyst support surface. The catalyst support has a surface area of about 50 to about 150 m.sup.2 /gram, a porosity of less than about 1 cm.sup.3 /gram, and a pore-size distribution such that less than about 10 percent of the pores present in the catalyst have a pore diameter greater than about 750 Angstroms. The cesium ions are present in an amount of about 4 to about 10 percent by weight, based on the weight of the catalyst. Also disclosed are methods of making the catalyst. One method contemplates combining, with agitation, a silica sol and a cesium compound able to provide cesium in the +1 oxidation state on the catalyst support surface. The silica sol has a silica particle diameter of about 50 to about 200 Angstroms. The silica sol and the cesium compound are combined in relative amounts sufficient to produce a freely-flowing slurry having a Cs/(SiO.sub.2 +Cs) weight ratio of about 0.04 to about 0.1. The freely-flowing slurry is solidified to a gel which is then dried to a crushable solid state. The dried gel is calcined for a time period sufficient to remove primarily adsorbed moisture therefrom.