Catalyst, method for producing catalyst, and method for producing unsaturated carboxylic acid and/or unsaturated carboxylic acid ester

The purpose of the present invention is to provide a catalyst with which an unsaturated carboxylic acid represented by methyl methacrylate and/or an unsaturated carboxylic acid ester can be produced with high selectivity. The problem is solved by a catalyst which contains one or more elements selected from the group consisting of boron, magnesium, zirconium, hafnium and titanium, one or more elements selected from the group consisting of alkali metal elements, and silica, and which has a peak height ratio I2/I1 of 0-1.2, where I1 is a peak height at 417 +/-10 cm and I2 is a peak height at 1050 +/-10 cm as determined by Raman spectroscopy. 本发明的目的在于提供一种能够以高选择率制造以甲基丙烯酸甲酯为代表的不饱和羧酸和/或不饱和羧酸酯的催化剂。通过如下催化剂来解决课题，该催化剂含有选自硼、镁、锆、铪和钛中的1种以上的元素、选自碱金属元素中的1种以上的元素、以及二氧化硅，并且将通过拉曼光谱分析而得到的417±10cm－1处的峰高设为I1、将1050±10cm－1处的峰高设为I2时，峰高之比I2/I1为0～1.2。