A kind of preparation method of highly dispersed supported nickel phosphide catalyst

Abstract

The invention provides a preparation method of a supported nickel phosphide catalyst that catalyzes the hydrodeoxygenation of phenol and its derivatives. The catalyst is a supported nickel phosphide. The steps include: 1. Dissolving nickel nitrate hexahydrate in deionized water to form solution; 2. Add the carrier, stir and heat continuously; 3. Weigh urea and add it to the obtained solution, and add concentrated nitric acid; 4. Add the solution obtained in step 3 to the suspension in step 2 drop by drop, heat up after dropping, and continue the reaction 5. Suction filtration, washing with deionized water, until the filtrate is neutral, drying overnight in an oven to obtain a gray-black solid; 6. Prepare acetic acid-sodium acetate buffer solution, then add sodium hypophosphite and continue to stir and heat up, slowly Add the precursor compound; 7. After the reaction, filter with suction and wash with deionized water until the filtrate is neutral, dry in an oven overnight, heat-treat in a chemical atmosphere and anneal at lower temperature to obtain a supported nickel phosphide catalyst. The catalyst obtained by the method of the invention has good dispersion, small particle size and good HDO activity.

Description

technical field [0001] The invention relates to the technical field of catalysts, in particular to a preparation method of a highly dispersed supported nickel phosphide catalyst and its application in the reaction process of biomass oil hydrodeoxygenation. Background technique [0002] With the development of the world economy, the demand for energy has increased sharply, and oil reserves have continued to decrease. The world is facing enormous energy pressure. At the same time, the environmental pollution caused by fossil energy has always been a hot issue of concern to the world. Therefore, actively It is very important to find alternative energy sources to relieve the pressure on energy and environment. In order to achieve sustainable social and economic development, some developed countries have successively proposed legislative policies to gradually replace traditional fossil energy with renewable energy, in order to reduce human dependence on fossil fuels and reduce gr...

AI Technical Summary

Problems solved by technology

[0003] At present, the hydrodeoxygenation (HDO) catalysts that have been studied more are: (1) Transition metal sulfides: During the HDO reaction, the S in the transition metal sulfide catalysts is easily replaced by O in the oxygen-containing compound to form an active phase Loss of structure, leading to catalyst deactivation

In addition, the by-product water will be generated in the HDO process, and the active phase of sulfide will be oxidized by water to become sulfate, the activity will decrease, and the catalyst will be deactivated

(2) Transition metal catalysts: Transition metal Ni catalysts are widely used in the hydrogenation reaction of biomass, but metal Ni catalysts are usually deactivated due to water poisoning, catalyst sintering and carbon deposition in the HDO process.

(3) Noble metal catalysts: Noble metal catalysts have high HDO activity and selectivity, especially the selectivity of naphthenes, such as Pd, Pt, Rh, Ru, etc., but their general price is high, resources are limited, and they are easy to deposit carbon. Under the constraints of these defects, it is difficult for precious metals to be applied on a large scale in industrial production.

At present, the impregnation method is used to use Al-containing molecular sieves such as HZSM-5 and Hβ or Al 2 o 3 When the nickel phosphide catalyst is synthesized as a carrier, it is calcined at high temperature and H 2 -Al will react with phosphorus species in the catalyst precursor during the TPR process, resulting in phosphorus loss, so it is difficult to synthesize this type of supported nickel phosphide catalyst

Moreover, the catalyst particle size obtained by the impregnation method is large and the dispersion is uneven. In order to improve the reactivity of the catalyst, it is urgent to reduce its grain size and increase the degree of dispersion.

Images