Load catalyst and preparation method and application thereof as well as method for preparing low carbon olefin by methane oxidative coupling

Abstract

The invention discloses a load catalyst. The catalyst comprises a carrier and a metal active component loaded on the carrier, wherein the carrier is barium titanate, the content of the carrier is 60wt%-98wt% of the total weight of the catalyst, and if the content of the carrier takes 100 weight parts, the content of the active component is 1.5-30 parts by weight metered by metal elements. The invention also provides a preparation method and application of the load catalyst, and a method for preparing low carbon olefin by methane oxidative coupling. The load catalyst provided by the invention has the advantages of high activity during the preparation of low carbon olefin by methane oxidative coupling, and good stability of long-time operating property.

Description

technical field [0001] The invention relates to a supported catalyst, its preparation method and application, and a method for preparing low-carbon olefins through oxidative coupling of methane. Background technique [0002] The methane oxidative coupling reaction is to use methane to directly convert low-carbon hydrocarbons. The reaction process is to form methyl radicals under the action of catalysts and oxygen species, and then methyl radicals are coupled to form ethane, which is dehydrogenated to ethylene. The reaction process is a high temperature and strong exothermic process. Since the first paper on the oxidative coupling of methane to ethylene in 1982 [Keller G E, Bhasin M W, Synthesis of ethylene via oxidative coupling of methane. Determination of active catalysis, J.Catal., 1982 ,73(1):9-19], the oxidative coupling of methane, a process that directly utilizes natural gas, has attracted widespread attention worldwide. The oxidative coupling of methane to light ole...

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Problems solved by technology

[0004] CN1696084A discloses that the active component is silver, and the carrier is a catalyst such as silicon dioxide, aluminum oxide, etc. Although this catalyst can carry out methane oxidative coupling reaction at a lower temperature, its carbon dihydrocarbon yield is relatively low

[0006] CN1389293A discloses a multi-component catalyst containing variable valence metal oxides, alkali metals and rare earth oxides with silica as a carrier, which can obtain 33% methane conversion and 73.1% C in methane oxidative coupling reaction 2 + Hydrocarbon selectivity, but the reaction process needs to be carried out under pressure

[0008] The prior art uses mesoporous molecular sieve SBA-15 as a carrier. Since the oxidative coupling reaction of methane is a strong exothermic reaction, mesoporous molecular sieve SBA-15 as a carrier has limited tolerance to temperature; aluminum oxide is used as a carrier ; The yield of carbon two hydrocarbons is low; although silica is used as a methane oxidative coupling catalyst carrier, the tolerance temperature is higher, and the carbon two hydrocarbon selectivity is higher, but the literature "methane oxidative coupling W-Mn / SiO 2 Catalyst Stability Investigation" (Petrochemical Industry, 1995:24, 293-298) reported that after 1000h and 500h experiments with silica as a carrier catalyst, α-cristobalite has completely transformed into α-tridymite and α-SiO 2 quartz

Silica is used as a catalyst carrier under the conditions of methane oxidative coupling reaction (high temperature above 800 degrees, oxygen, and water), and it shows the instability of crystal structure during long-term operation, which will lead to a decrease in the stable operation time of the catalyst.

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