Density functional theory study of the selective oxidation of 5-Hydroxymethylfurfural (HMF) to 5-Hydroxymethyl-2-furancarboxylic acid (HMFCA) on the Silver oxide surface (001)

•The oxidation of HMF to 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) is done employing a cheap and commercially available catalyst Ag2O.•The selective 5-HMF oxidation to HMFCA on Ag2O(001) surface was investigated by density functional theory (DFT).•Three possible reaction pathways in multiple steps and their energetics were studied.•Through charge transfer, the catalysis mechanism onto the Ag2O (001) is understood.5-Hydroxymethylfurfural (HMF) is a highly useful building-block in the manufacture of a wide range of furanic compounds, it offers strategies to replace fossil source-based starting materials in chemical industry. Recently, successful oxidation of HMF to 5-hydroxymethyl-2-furancarboxylic acid (HMFCA) employing a cheap and commercially available catalyst viz. Ag2O has been reported. However, the theoretical calculations of this important oxidation process which can complement the experimental work has not been reported thus far; theoretical calculations are critical since they provide great help in thorough understanding of the mechanism of HMF oxidation. In this work, different mechanistic pathways have been carried out using density functional theory (DFT) calculations, to study the energy states of different intermediates that are likely to be formed on the Ag2O (001) surface. The most stable configurations were investigated and compared in order to confirm the most probable path which requires less activation energy to provide more insights into the experimental results.