Methane conversion into different hydrocarbons or oxygenates: current status and future perspectives in catalyst development and reactor operation

Abstract

This Perspective highlights recent developments in methane conversion into different hydrocarbons and C1-oxygenates. Our analysis identified possible directions for further research to bring the above approaches to a commercial level.

Oxidative Methane Conversion to Ethane on Highly Oxidized Pd/CeO2 Catalysts Below 400 °C

“…Using a continuous‐flow reactor is preferred for direct methane conversion. O 2 as an oxidant, instead of H 2 O 2 or N 2 O, is preferred for oxidative methane conversion . Because conventional oxidative coupling of methane generates radicals at high temperatures of >700 °C resulting in various side products, catalysts enabling surface reaction at much lower temperatures are desired.…”

Data Driven Determination of Reaction Conditions in Oxidative Coupling of Methane via Machine Learning

“…In particular, oxidative coupling of methane (OCM) is chosen as a prototype reaction where the reaction involves conversion of methane to C 2 compounds ethylene and ethane. Typically, the OCM is performed on basic catalysts containing alkaline or alkaline earth metals at a very high temperature ranging from 973–1173 K for abstraction of H from CH 4 to form CH 3 radical intermediates of the C 2 compounds . To put the OCM towards an industrial application, the catalytic reaction systems should have high C 2 selectivity by suppressing undesirable reactions – in particular, oxidation of CH 3 radicals on catalyst surface as well as in gas phase – while maintaining CH 4 conversion rate .…”

“…In addition, high durability is required for the catalyst materials to stably produce the C 2 compounds at such high reaction temperatures . In order to develop the OCM catalysts with these functions, hundreds of inorganic materials have been investigated as summarized in the previous review articles . Among the reported catalysts, Mn‐Na 2 WO 4 /SiO 2 exhibits relatively high activity, selectivity, and stability for the OCM .…”

“…The catalytic performance of Mn‐Na 2 WO 4 /SiO 2 has been further improved by meso‐ordered structure of SiO 2 support as well as by a membrane reactor with separated feeding of CH 4 and O 2 . However, no catalytic reaction systems affording sufficient C 2 yield and selectivity for practical large‐scale application have been developed . One can consider that OCM involves complex reaction conditions; therefore, machine learning is implemented to reveal how reaction conditions act in high dimension during the OCM reaction.…”

High Catalytic Activity of Crystalline Lithium Calcium Silicate for Oxidative Coupling of Methane Originated from Crystallographic Joint Effects of Multiple Cations

“…A recent concern of petroleum depletion has led to renewed attention to methane as an alternative carbon resource . While methane is relatively abundant in natural gas, its particular stability hinders facile conversions into commodity chemicals by partial oxidation . The oxidative coupling methane (OCM) to C 2 hydrocarbons such as C 2 H 6 and C 2 H 4 is a possible route, see [Eqs.…”