ABSTRACT

Partial oxidation of methane (POM) offers a promising option to produce syngas for downstream processes such as hydrogen production and Fischer-Tropsch processes. POM in fixed-bed reactors requires an oxygen separation plant with high operation cost and safety risks. On the contrary, membrane reactors can provide an improved process by integrating both oxygen separation and catalytic reaction processes. With many advantages including high purity and efficient oxygen separation from the air at the catalytic reaction conditions, mixed ionic-electronic conducting membranes (MIEC) caught great attention in the scientific research field over the past two decades. In this review, POM using different catalysts in fixed-bed reactors was firstly summarized with emphasizing on perovskite-based catalysts, and then the material screening of MIEC membrane reactors was introduced and linked to the selection of conventional and perovskite catalysts. The catalytic activity, reaction mechanisms, and emerging challenges have been analyzed. Furthermore, future research directions have been outlined by highlighting the effect of electronic properties, continuous reduction-oxidation in the presence of oxygen flux, and chemical reaction mechanism on membrane/catalyst.

摘要

甲烷的部分氧化（POM）为生产下游工艺（例如制氢和费-托工艺）的合成气提供了一种有希望的选择。固定床反应器中的POM需要氧气分离装置，其运行成本高且存在安全风险。相反，膜反应器可以通过整合氧分离和催化反应过程来提供改进的过程。混合离子电子导电膜（MIEC）具有许多优点，包括在催化反应条件下具有高纯度和有效地从空气中分离氧气的特性，在过去的二十年中引起了科学研究领域的极大关注。在这篇综述中，首先总结了在固定床反应器中使用不同催化剂的POM，重点是钙钛矿基催化剂，然后介绍了MIEC膜反应器的材料筛选，并将其与常规和钙钛矿催化剂的选择联系起来。分析了催化活性，反应机理和新出现的挑战。此外，通过突出电子性质，在氧气通量存在下的连续还原-氧化以及对膜/催化剂的化学反应机理的影响，概述了未来的研究方向。