Interface and defect engineer of titanium dioxide supported palladium or platinum for tuning the activity and selectivity of electrocatalytic nitrogen reduction reaction

Electrocatalytic N 2 reduction reaction (NRR) under ambient condition is considered as an alternative and environmental-friendly technique to substitute the conventional process of Haber-Bosch for NH 3 production. However, there are still hurdles for researchers to control the balance between N 2 activation and competitive hydrogen evolution reaction (HER) to obtain high selectivity of NRR. Herein, we synthesized Pt/TiO 2 and Pd/TiO 2 hybrids by using laser ablation in liquid (LAL) technology combined with hydrothermal treatment and compared their activity and selectivity of N 2 reduction. The results concluded that Pt/TiO 2 exhibited a higher NH 3 yield rate whereas Pd/TiO 2 achieved a better FE for artificial N 2 fixation, confirming that enhanced activity surely needs more electrons and protons to participate in the reaction, but the limited protons and electrons furnishing could restrain HER activity and improve selectivity of NRR. Comparing with Pt/TiO 2 , Pd/TiO 2 hybrids could serve as a superior catalyst for keeping a balance relationship between HER and NRR to realize excellent selectivity and high yield rate simultaneously in an alkaline solution. Overall, this work will provide a significant practice to rational design electrocatalysts for NRR at ambient conditions and Pd-based materials might open an electrocatalyst paradigm to solve the global energy and ecological crisis.