Method for preparing modified Pt-based catalysts with La loaded by metal organic framework materials used as carriers and application of modified Pt-based catalysts

Abstract

The invention discloses a method for preparing modified Pt-based catalysts with La loaded by metal organic framework materials used as carriers and application of the modified Pt-based catalysts. Themethod includes adding deionized water into terephthalic acid, chromic nitrate nonahydrate and hydrofluoric acid mixtures to obtain first mixtures; crystallizing the first mixtures for a period of time and then filtering and drying the first mixtures; adding N, N-dimethylformamide into the first mixtures and carrying out stirring reaction; filtering, washing and drying reaction products to obtainthe metal organic framework materials which are used as the carriers; adding chloroplatinic acid aqueous solution and precursor salt into the metal organic framework materials; carrying out reaction,then drying and calcining reaction products and carrying out reduction on the reaction products to obtain the ultimate required modified Pt-based catalysts La-Pt / MIL-101. The method and the application have the advantages that the modified Pt-based catalysts are low in cost, high in universality, free of equipment corrosion and good in cycle performance and are economical, effective and environmentally friendly; the modified Pt-based catalysts are high in activity and para amino phenol selectivity under relatively mild reaction conditions when applied to processes for preparing para amino phenol by means of nitrobenzene one-step hydrogenation rearrangement, production conditions can be improved, the production cost can be reduced, and the quality of products can be enhanced.

Description

technical field [0001] The invention relates to the field of material preparation, in particular to a preparation method and application of a La-modified Pt-based catalyst supported by a metal-organic framework material. Background technique [0002] P-aminophenol (hereinafter referred to as PAP) is an important chemical raw material and organic intermediate in today's society. It is widely used in medicine, dyes, rubber and photography industries. In my country, PAP is mainly used in the pharmaceutical industry. As a pharmaceutical intermediate, PAP can be used to synthesize paracetamol (paracetamol), paracetamol, clofibrate, vitamin B1, propanol, compound agents nicotinamide, lauanol, 6- Hydroxyquinoline and other drugs, among which paracetamol is the most consumed. In the 1970s, researchers discovered that taking antipyretic and painkillers such as acetanilide and phenethyl ether would decompose into harmful components in the body. The United States, Britain, Japan and ot...

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Problems solved by technology

Chinese patent CN1283612A discloses a supported Pt / γ-alumina-MEO catalyst, which catalyzes nitrobenzene under sulfuric acid conditions. The loading of active components is 0.5-5%. Although the selectivity of p-aminophenol can reach 70 %, the reaction is carried out under the sulfuric acid system, which needs to be neutralized with alkaline substances, which causes inconvenience to product separation, and will generate some waste water at the same time, which is more serious to environmental pollution and has a certain corrosion effect on the catalyst. Complex and large dosage, high product cost, and high content of metal oxidation waste, it is difficult to be used as medicine

Chinese patent CN103553943A discloses to use Pt / C, Pt-Sn / Al under the condition of carbon dioxide and water system 2 o 3 , Pd-CaCO 3 -PbO / PbAC 2 A series of catalysts, under the pressure of hydrogen 0.3-5MPa, carbon dioxide 0.5-10MPa, temperature 80-170 ℃, reaction time 0.5-12h, selectivity is about 5-70%, but the reaction pressure of hydrogen and carbon dioxide is relatively high , the reaction temperature is high, the reaction time is long, the requirements for the reaction device are very high, the preparation of the catalyst is complicated and the content of the active component of the catalyst is high. If the platinum carbon catalyst is used, the pores of the activated carbon are relatively deep, which is not good for the desorption of the product.

[0005] In summary, the yield of nitrobenzene in the above process routes is not very high, and some process routes have relatively harsh reaction conditions