The promotional role of water in heterogeneous catalysis: mechanism insights from computational modeling

Water is the key to life in our planet. As one of the most abundant resources on the earth, water may play important roles in chemical reactions in addition to being a reaction medium. In this review, we highlight recent advances in experimental observations and mechanistic understanding of the promotional role of water in chemical reactions, with an emphasis on the essential effects of water in heterogeneous catalysis. As water may exist in molecular state or dissociate to hydroxyl (OH) and hydrogen (H) species on catalyst surfaces, we have outlined the roles of water from three aspects: (1) the promotional role of molecular water including the solvation-like effect and water-mediated H-transfer, (2) the promotional role of OH/OH ⁻ and H/H⁺ species, and (3) some miscellaneous effects of water, such as water-assisted carbon removal, surface reconstruction, and active sites blocking. The results discussed here provide a fundamental understanding of the promotional role of water in heterogeneous reactions and may inspire the theoretical studies of water effects on other fields of chemistry and atmospheric science as well. WIREs Comput Mol Sci 2016, 6:679–693. doi: 10.1002/wcms.1272. For further resources related to this article, please visit the WIREs website.