Preparation method of double effect catalyst for high selective oxidation of methane to prepare dimethoxymethane

Abstract

The invention belongs to the field of solid catalyst for oxidation reactions for preparing dimethoxymethane, and especially relates to a preparation method of a double effect catalyst for high selective oxidation of methane to prepare dimethoxymethane. The preparation method comprises the following steps: (1) weighing oxalic acid and sulfate, adding distilled water containing ethanol, and stirring to dissolve the solid to obtain a solution A; (2) adding ammonium metavanadate into the solution A obtained in the step (1), and stirring to dissolve the solid ammonium metavanadate to obtain a solution B; (3) mixing burned TiO2 with the solution B obtained in the step (2), evenly stirring the solution at a room temperature, and allowing the system to stand still; (4) transferring the product obtained in the step (3) to a reactor, and heating the product; (5) after heating, taking out the product obtained in the step (4) from the reactor, cooling, filtering the white precipitate in the reactor, filtering, drying in vacuum, and burning the powder obtained in the drying step to obtain the target product. The catalyst has the advantages that the V2O5 is well dispersed, and the catalyst has an oxidation activity and acid center.

Description

technical field [0001] The invention belongs to the field of solid catalysts for the oxidation of dimethoxymethane, in particular to a method for preparing a double-effect catalyst for the highly selective oxidation of methanol to dimethoxymethane. Background technique [0002] Dimethoxymethane is a colorless, non-toxic, environmentally friendly chemical raw material. Due to its high oxygen content and cetane number, it has attracted much attention as a diesel additive with excellent performance in recent years. Traditionally, dimethoxymethane is synthesized by a two-step method. Methanol is first oxidized to formaldehyde, and then formaldehyde and methanol are condensed to form methylal. The first step of the process uses silver at 873-923K or iron-molybdenum catalyst at 573-703K, and the reaction temperature is relatively high; the second step uses acid catalysts such as acidic cation exchange resin, AlCl3, sulfuric acid, etc. This traditional process has problems such a...

AI Technical Summary

Problems solved by technology

The current method of introducing acid centers is to modify by post-treatment of liquid acid aqueous solution or salt solution containing acid radicals, but after modification, V 2 o 5 The dispersibility and redox properties of the catalyst change, which reduces the reactivity and selectivity of the catalyst, that is, the selectivity of dimethoxymethane decreases, and the acid center is easy to lose, thereby reducing the catalytic activity.

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