Palladium metallene confined on MXene with increased hydroxyl binding strength for highly efficient ethanol electrooxidation

Rational design and synthesis of high-performance electrocatalysts for ethanol oxidation reaction (EOR) is crucial to large-scale commercialization of direct ethanol fuel cells, but it is still an incredible challenge. Herein, a unique Pd metallene/Ti(3)C(2)T(x) MXene (Pdene/Ti(3)C(2)T(x))–supported electrocatalyst is constructed via an in-situ growth approach for high-efficiency EOR. The resulting Pdene/Ti(3)C(2)T(x) catalyst achieves an ultrahigh mass activity of 7.47 A mg(Pd)(−1) under alkaline condition, as well as high tolerance to CO poisoning. In situ attenuated total reflection-infrared spectroscopy studies combined with density functional theory calculations reveal that the excellent EOR activity of Pdene/Ti(3)C(2)T(x) catalyst is attributed to the unique and stable interfaces which reduce the reaction energy barrier of *CH(3)CO intermediate oxidation and facilitate oxidative removal of CO poisonous species by increasing the Pd–OH binding strength.