Phosphotungstic acid and propyl sulfonic acid functionalized silicon oxide composite material in non-hydrochloric acid system and preparation method thereof

Abstract

The invention discloses a functionalized silicon oxide composite material with a mesoporous structure based on phosphotungstic acid and sulfonic acid and a preparation method, and belongs to the technical field of composite materials. The structure of the composite material provided by the invention is pr-SO3H-OMS / H3PW12O40. According to the composite material, an ordered mesoporous silicon-basedmaterial OMS is used as a carrier, two active ingredients, namely Keggin type phosphotungstic acid and propyl sulfonic acid, are loaded on the carrier, the ordered mesoporous silica-based hybrid material OMS is formed by co-condensing an organic silicon source (3-mercaptopropyl) triethoxysilane (MPTES) and an inorganic silicon source tetraethoxysilane (TEOS), and the loading capacity of phosphotungstic acid is 17.04 wt% to 24.65 wt%. The pr-SO3H-OMS / H3PW12O40 composite material is designed and prepared by combining a one-step hydrolytic co-condensation method and a hydrothermal treatment technology, the use of hydrochloric acid in the traditional ordered mesoporous silicon-based material preparation process is abandoned, the preparation process is simple, and the process is pollution-free.Due to the synergistic effect between propyl sulfonic acid groups and phosphotungstic acid, the pr-SO3H-OMS / H3PW12O40 catalyst with double acidic sites shows very high catalytic activity on esterification reaction of oleic acid and methanol, the reaction conversion rate is high, the product purity is high, the reaction process is clean and pollution-free, and the reusability of the catalyst is good.

Description

technical field [0001] The invention relates to the technical field of composite materials, in particular to a silicon oxide composite material with mesoporous structure synthesized based on phosphotungstic acid and sulfonic acid functionalization in a non-hydrochloric acid system and a preparation method thereof. Background technique [0002] Biodiesel is a renewable fuel composed of a series of long-chain fatty acid methyl esters. Due to the non-renewable characteristics and depletion of fossil energy, biodiesel has become the most promising substitute for fossil energy. Biodiesel has many advantages, non-toxic and harmless, renewable, a large number of raw materials for production are easy to obtain, a mixture of 80% petroleum diesel and 20% biodiesel (called B20) can be directly used in unmodified diesel engines, so the current biodiesel It has received great attention from scientific research and technical personnel. In the current study, biodiesel is usually obtained...

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Problems solved by technology

However, these two methods not only have a long experimental period and complicated operation process, but also generally interact with van der Waals force or hydrogen bond between heteropolyacid and molecular sieve, which is very easy to dissolve and desorb during the reaction process, which reduces the reusability of the catalyst.

So far, the synthesis of silicon-based ordered mesoporous materials requires a strong acid solution (usually hydrochloric acid) as the synthesis medium. The use of a large amount of hydrochloric acid causes serious environmental problems and severely corrodes production equipment.

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