Modified boron nitride supported metal catalyst and preparation method and application thereof

Abstract

The invention provides a modified boron nitride supported metal catalyst and a preparation method and application thereof, and belongs to the technical field of catalytic materials. The modified boronnitride supported metal catalyst provided by the invention comprises a modified boron nitride carrier and an active component loaded on the modified boron nitride carrier, wherein the active component comprises one of metal ruthenium, nickel, silver and copper; the mass fraction of the active component in the modified boron nitride loaded metal catalyst is 0.1-5%; defect sites and functional groups exist on the surface of the modified boron nitride carrier; the defect sites comprise a nitrogen defect site and a boron defect site; the functional group is a hydroxyl functional group and/or an amino functional group. Results of the embodiment show that when the catalyst provided by the invention is used for catalyzing hydrogenation of dimethyl oxalate, the conversion rate of dimethyl oxalateis 95.4-99.9%; the selectivity of methyl glycolate is 95.0-98.9%, no obvious inactivation phenomenon exists after continuous reaction is conducted for 100 h, and the structure and the performance arekept stable.

Description

technical field [0001] The invention relates to the technical field of catalytic materials, in particular to a modified boron nitride supported metal catalyst and its preparation method and application. Background technique [0002] Methyl glycolate (MG) is an important intermediate in organic synthesis and pharmaceutical synthesis. It is also an excellent solvent for various materials such as rubber, resin and cellulose, and can be used as a solvent for the degradable plastic polyglycolic acid (PGA). Synthetic monomers, therefore, the development of low-cost preparation of MG has become a trend. Originating from the domestic coal-to-ethylene glycol (EG) technology and the advantages of device capacity, the selective catalytic hydrogenation of coal-based synthesis gas to dimethyl oxalate (DMO) to MG is a potential green technology with good technical and economical advantages. The chemical route is in line with the relatively abundant coal resources in our country. The reac...

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Problems solved by technology

[0005] (1) The optimal mass fraction ratio of the metal active components in the catalyst is mostly 20-30%. The amount of metal used is large, and the cost of the catalyst is also high. The subsequent recovery of the catalyst also faces higher processing costs and environmental protection pressure;

[0006] (2) The size of the catalyst is large, the exposed metal active surface is small, the metal sites are easy to agglomerate, and the proportion of metal components actually participating in the reaction is very small, resulting in low metal utilization and low reactivity per unit mass of metal ;

[0007] (3) The stability of the catalyst is poor. The DMO hydrogenation reaction often requires a temperature of about 200°C to be activated. Higher temperatures lead to Ostwald ripening of the metal components in a longer reaction time, and the size of the active metal gradually increases. Large, the reaction is gradually inactivated, and it is difficult to reverse

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