Micro reactors for measurement and analysis of thermochemical gas-solid reactions

•Micro gas-solid reactors can be classified on basis of the heating and loading methods.•Heating rate and gas-solid contacts need to be considered in selecting and operating microreactors.•Each reactor has its advantages and limitations for thermal analysis of gas-solid reactions.•Continuous development of more advanced microreactors and analyzers is needed to meet the challenges. Micro reactors are the essential part of thermal analysis techniques for characterizing gas-solid thermochemical reactions. The dynamic and diversified needs for investigating various complex materials and gas-solid reactions have led to the development of a variety of different microreactors over the years. Solid particles in microreactors are normally heated by furnaces from outside, resistive elements from inside, direct contact with bed particles, or other non-resistively methods. Solid particles can be fixed or fluidized in reactors where gas-solid contacts vary from diffusion-dominated to nearly diffusion-free conditions. Based on these characteristics, in this article we presented a broad classification for microreactors used for thermal analysis of gas-solid reactions. For each of the most popularly used microreactors, their features and limitations are briefly reviewed. By addressing the diversity of the microreactors used in the field of thermal analysis, the review aims at providing general guidance for the selection and operation of the microreactor to satisfy one's practical specific needs. [Display omitted]