Comparative study on the reaction mechanism of 5-hydroxymethyl furfural on Pd(111) and Cu(111).

Context: In this work, a comparative study on the catalytic conversion of 5-hydroxymethyl furfural (HMF) to 2,5-bis(hydroxymethyl)furan (BHMF) on precious Pd(111) and nonprecious Cu(111) was systematically performed. On the basis of the calculated activation energy (E) and reaction energy (E), the optimal energy path for the hydrogenation of HMF (F-CHO) into BHMF (F-CHOH) on Pd(111) is as follows: F-CHO + 2H → F-CHOH + H → F-CHOH; the minimum reaction path on Cu(111) is F-CHO + 2H → F-CHO + H → F-CHOH. On Cu(111), the formation of F-CHOH from F-CHO hydrogenation is the rate-determining step because it has the highest reaction energy barrier and the smallest rate constant.