Taming Pt 5d state occupancy via Pt-O-Mn electronic linkage for enhanced dehydrogenation activity

The enhancement of catalytic activity is always limited by the dilemma in activation and desorption due to Sabatier principle. Locating the Sabatier optimum by manipulating catalyst electronic structure has been a long-standing challenge in heterogeneous catalysis. Herein, we presented a generic strategy to continuously tailor the Pt 5d state occupancy via tuning the Pt-O-Mn electronic linkage over Al2O3-confined MnOx islands, aiming at accommodating the C-H cleavage and product desorption capabilities in dehydrogenation of liquid organic hydrogen carriers (monocyclic/bicyclic hydrides). Rising Mn valence can decrease the Pt 5d state occupancy through more electron transfer from Pt 5d to O 2p due to the strong p-donation of O 2p to Mn 3d. This will lead to the lower initial C-H activation energy barrier while higher product desorption energy barrier. An intermediate Pt 5d filling of similar to 8.4 in Pt-Mn2O3/Al2O3 enables the balanced level of product desorption and C-H activation, thus ensuring a superior dehydrogenation activity. The electron structure-adsorption-performance modulation mechanism described herein provides a benchmark to locate the Sabatier optimum for the metal catalyst design.