Nano carbon-covered alumina support-based preparation process of dehydrogenation catalyst

Abstract

The invention relates to a nano carbon-covered alumina support-based preparation process of a dehydrogenation catalyst. The preparation process is characterized by comprising the following steps of: preparing nano-scale carbon-covered gamma-AL2O3 through the steps of gelling, hydrolytic precipitation, pre-burning, and N2 thermal treatment by using an inorganic aluminum salt as an aluminum source and starch as a carbon source and adopting a 'One Pot' method; and loading active metal components by using the gamma-Al2O3 support, and performing activation to obtain a catalyst which ensures that an organic hydride has high dehydrogenation performance. The catalytic material combines dual advantages of the scale effect of a nano material as a catalyst and high anti-coking performance of a carbon-covered alumina material, thereby showing very high catalytic activity. Low-cost poly-hydroxyl starch is used in the preparation process of the carbon-covered gamma-Al2O3 support and is gelatinized into a gel; and compared with the conventional carbon-covered preparation process which adopts volatile hydrocarbons as a carbon source, the raw materials are easy to obtain, and are reproducible and environmentally-friendly.

Description

technical field [0001] The invention relates to catalyst preparation technology, in particular to a nanometer carbon-coated alumina material and a preparation method of a dehydrogenation catalyst using the material as a carrier. Background technique [0002] In recent years, the liquid organic hydride hydrogen storage technology based on the chemical reaction method has attracted the attention of many countries due to its large hydrogen storage capacity, high energy density, safe and convenient liquid storage and transportation, and is expected to play an important role in the future hydrogen energy storage and transportation. Unsaturated aromatics and corresponding hydrides (cycloalkanes), such as benzene-cyclohexane, toluene-methylcyclohexane and other organic substances, can be hydrogenated and dehydrogenated without destroying the main structure of the carbon ring, thereby achieving large-scale and low-cost hydrogen storage. [0003] The liquid organic hydride hydrogen ...

AI Technical Summary

Problems solved by technology

[0019] To sum up, the alumina cores used in these documents and patents for carbon coating are all purchased from commercial products or prepared first and then used for carbon coating after further treatment, and these alumina core particles are relatively large (micron to mm level), after the outer surface of larger particles of alumina is covered by carbon, the micropores of the alumina particles are blocked, so the original inner surface of the alumina particles cannot be effectively used, and the mass and heat transfer process is affected to a certain extent. Performance is also degraded

In addition, from the perspective of the preparation procedure, the reported methods require two steps of preparing alumina and coating carbon with alumina, and the process is relatively long.

Moreover, for the carbon coating process, these patents or documents either use gaseous carbon sources (such as methane, ethylene or carbon monoxide) or use volatile organic compounds (such as olefins, aromatics, alkanes) as carbon sources at high temperatures (500-800 ° C) Covering alumina after pyrolysis, the process is flammable and explosive, requires strict airtight treatment, and there are safety problems

At the same time, a large amount of combustible organic waste gas is produced after pyrolysis, which may cause pollution and deteriorate the working environment

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