Brønsted-evans-polanyi and transition state scaling relations of furan derivatives on pd(111) and their relation to those of small molecules

Brønsted-Evans-Polanyi (BEP) and transition state scaling (TSS) linear free energy relations are extended to C-H, O-H, C-O and C-C bond breaking reactions occurring on the ring and the functional groups of furan (hydrofuran, dihydrofuran, trihydrofuran, and tetrahydrofuran) and furfural derivatives (e.g., furfural, furfuryl alcohol, methyl furan, etc.) on Pd(111). The relations perform statistically as well as those for small molecules reported previously. Hydrogenation/dehydrogenation reactions have smaller deviations compared to C-C and C-O bond breaking ones. This is in line with the degree of structural change during reaction and agrees with observations in previous works. We conclude that BEP relations developed for small molecules are not statistically different from those developed for furanics. A universal BEP relation is not statistically different from most of the BEP relations developed for furanics, with the exception of C-O, O-H and C-H scission reactions at the functional group, for which only the intercept is statistically different. Small-molecule BEP relations perform adequately for exploring biomass-relevant chemical kinetics on metal surfaces with higher accuracy than the universal BEP relation but lower accuracy than the BEPs of furanics. Finally, we make general observations about the effect of structural change and reaction energy on the accuracy of linear free energy relations on metal surfaces.