Transient Thermal Engineering of Pt@rGO Nanocatalysts via Oxygen Anchoring and Chlorine Coordination for Efficient Hydrogen Generation

The accelerating transition to clean hydrogen energy demands highly efficient and stable platinum‐based electrocatalyst for the hydrogen evolution reaction (HER). However, achieving uniform low‐Pt‐loading catalysts remains challenging due to weak interfacial interactions and inadequate dispersion control. Herein, we developed a synergistic interfacial coordination engineering strategy through integrating freeze‐drying with transient non‐equilibrium Joule heating, enabling the ultrafast synthesis of uniformly dispersed 1.84 ± 0.58 nm Pt nanoclusters on the reduced graphene oxide (i.e., Pt@rGO‐T) within 20 s. Structural characterizations and theoretical calculations reveal that oxygen anchoring sites and chlorine coordination cooperatively strengthen the electron–metal–support interaction and modulate the Pt d‐band center, thereby tuning the H* adsorption free energy toward a more favorable, near‐thermoneutral range. Notably, this interfacial configuration may promote interfacial modulation and possible H* migration between Pt nanoclusters and the rGO support. As a result, the Pt@rGO‐T delivers low overpotentials of 29.6 and 73.0 mV at 10 and 100 mA cm −2 , respectively, along with a high mass activity of 6.23 A mg −1 and excellent durability over 200 h. This transient thermal engineering strategy offers a generalizable pathway for the rational design of interfaces and coordination environments in advanced noble metal‐based electrocatalysts.