Catalyst for carbon dioxide hydrogenation and toluene aromatic ring alkylation as well as preparation method and application of catalyst

Abstract

The invention relates to a catalyst for carbon dioxide hydrogenation and toluene aromatic ring alkylation as well as a preparation method and application of the catalyst. The catalyst is prepared by mixing a Cu-based catalyst and an HZSM-5 molecular sieve. The Cu-based catalyst is a mixed oxide composed of a Cu body and modified metal, and the mass ratio of the Cu-based catalyst to the surface HZSM-5 molecular sieve is 1: 3 to 3: 1. The modified metal is one of Zr, Zn, Ce and Ti, the content of the Cu oxide is 50 wt%-95 wt%, and the content of the modified metal is 5 wt%-50 wt%. Compared with the prior art, the method has the advantages that the methanol-to-olefin side reaction caused by an improper methanol / toluene feeding ratio can be reduced, and the production efficiency of xylene is improved; meanwhile, the isomerization reaction of xylene can be inhibited, and the selectivity of p-xylene in the product is improved; and the catalyst has good stability at a high temperature, provides a new idea for carbon dioxide hydrogenation and toluene aromatic ring alkylation, and has a good industrialization prospect.

Description

technical field [0001] The invention relates to a catalyst for producing p-xylene by hydrogenation of carbon dioxide and alkylation of toluene, in particular to a catalyst for hydrogenation of carbon dioxide and alkylation of toluene aromatic ring, its preparation method and application. Background technique [0002] CO 2 It is a part of the atmosphere and an indispensable gas in the earth's carbon cycle. Since the beginning of the industrial revolution, the vigorous development of human productivity has been accompanied by the ever-increasing demand for energy, so CO emissions from fossil fuel combustion 2 Gradually become atmospheric CO 2 main source of . [0003] During the period 1970-2003, global carbon dioxide emissions increased by an average of 1.7% per year, the CO emitted into the atmosphere by fossil fuel combustion 2 From 15 billion tons in 1970 to about 25 billion tons in 2003; from 2003 to 2011, with the rapid development of the industrial level of countrie...

AI Technical Summary

Problems solved by technology

[0009] CN110743609 A reported using Zr–Zn composite oxide and HZSM-5 coupling catalyst, using the high temperature stability of ZZO, xylene selectivity can reach 92.4%, but the same CO 2 Low conversion and toluene conversion, resulting in low p-xylene yield

[0010] The challenge of this reaction is to find suitable reaction parameters. Because low temperature and high pressure are favorable for the methanolylation of carbon dioxide and the optimal reaction temperature range for the alkylation of toluene is at a high temperature of 400°C-500°C, how to provide a stable production method under high temperature and high pressure conditions? Metal oxide catalysts for methanol intermediates are currently the main research direction

Images