Catalytic hydrogenation is important and widely used in many areas of the chemical industry, such as the fine chemical and pharmaceutical sectors. For example, the synthesis of ammonia via the Harber-Bosch process, one of the most important processes saving human beings from hunger, is the hydrogenation reaction with nitrogen over iron-based catalysts. Another good example is the hydrogenation of carbon monoxide using cobalt and iron catalysts via the Fischer-Tropsch process, producing value-added fuels from carbon monoxide and hydrogen. Conversion and selectivity toward desired products in hydrogenation are directly related to the performance of the catalyst, and, therefore, the design of active and stable catalysts is of particular importance. Traditionally, a variety of methods including impregnation, co-precipitation, deposition-precipitation, chemical vapor deposition, and ion-exchange have been employed to prepare active, selective, and stable catalysts for hydrogenation reaction. Recently, there have been attempts to use atomically dispersed catalysts for hydrogenation reaction to regulate the selectivity, but metal atoms of those catalysts are susceptible to sintering under an H₂ atmosphere at elevated reaction temperature due to high surface-free energy. A combination of various characterization techniques such as Fourier-transform infrared spectroscopy (FT-IR), high-resolution scanning and transmission electron microscopy, and X‐ray photoelectron spectroscopy (XPS) has been employed to characterize the catalyst structures, but the mixture of multicomponents (and the dynamic structures) of working catalysts has prevented us from fully understanding the structure-activity relationships and identifying the active sites. This Special Issue will feature articles on the synthesis and applications of heterogeneous catalysts for hydrogenation reaction wherein novelty arises from any of the following: (i) the synthesis and applications of new active, selective, and stable catalysts for hydrogenation; (ii) understanding of structure-activity relationship via in situ and in operando characterization of the dynamic structure of working catalysts under reaction conditions; (iii) the identification of the active sites and reaction kinetics.
Keywords: catalyst design; hydrogenation; structure-activity relationships; reaction kinetics; characterizations.