Engineering Adaptable Functional Interfacial Active Sites via Tuning Interfacial Electron Spillover Effect for Hydrogen Production

Heterogeneous catalysis plays a pivotal role in modern energy systems, particularly for safe hydrogen production via efficient ammonia decomposition. Cobalt (Co) emerges as one of the most active nonprecious metal catalysts with significant potential to replace expensive ruthenium (Ru). However, conventional Co catalysts with stiff-functional active sites hinder the dynamic control of metal–nitrogen bonding during the ammonia (NH 3 ) cracking process, ultimately limiting the catalytic activity enhancement. This study demonstrates a CeO 2 /Co/C catalyst featuring adaptable-functional interfacial active sites engineered via coupled orbitals. The Ce–O–Co orbital coupling drives the interfacial electron spillover effect, enabling dynamic tuning of Co–N bonding. Theoretical studies demonstrate that this dynamic tuning not only weakens the rigid adsorption of NH 3 at the Co sites but also significantly lowers the energy barriers for key steps, such as NH 3 activation (N–H cleavage) and N 2 recombination (N–N coupling), thereby promoting the kinetics of ammonia decomposition. The targeted-synthesized catalyst achieves hydrogen production rates of 59.23 mmol·g cat. –1 ·min –1 at 550 °C and maintains stability over 200 h, surpassing most top Co-based NH 3 decomposition catalysts. This work provides fundamental insights into orbital-coupled active site design and introduces an approach to contrive adaptive functional active sites to boost hydrogen production.