Revealing the catalytic activities of 3d–5d transition metals in C–O bond cleavage for biofuels: Insights from computational predictions and experimental validation

The cleavage of carbon–oxygen (C–O) bonds is a crucial transformation in various energy-related industrial processes. Guaiacol and its hydrodeoxygenation derivatives were selected as reaction substrates to systematically evaluate the catalytic activity of 3d–5d transition metals and certain oxides. A linear scaling relationship between bond orders and energy barriers was established through theoretical derivation and empirical benchmarking. Based on it, we developed a universal hybrid computational method named the bond order mapped barrier approach, which substantially diminishes the entry threshold and improves the efficiency of catalytic activity predictions. The method was employed to evaluate catalytic activity for C–O bond cleavage through the calculation of 3540 adsorption and 105 transition states, with the primary predictions validated by experimental results. The findings revealed that the theoretically calculated energy barriers exhibited a quasi-linear correlation with the natural logarithm of the experimentally determined rate constants. Notably, Re2O7 and Ni were identified as efficient catalysts in cleaving the C(sp2)–O bond, demonstrating performance comparable to Ru. To leverage the high activity of WO3 in cleaving C(sp3)–O bonds, we proposed a tandem catalytic strategy, which resulted in an apparent cyclohexane generation rate constant forty-seven times greater than that of Ru in experiments.