Dehydrogenation efficiency improvement of liquid organic hydrogen carrier via enhancing hydrogen bubble nucleation

Inhibited bubble behavior severely limits the dehydrogenation efficiency of liquid organic hydrogen carriers (LOHCs), yet bubble dynamics have received little attention compared to catalyst kinetics. Using dodecahydro- N -ethylcarbazole dehydrogenation over Pd/Al 2 O 3 as a model reaction, this study finds that the efficiency of pre-soaked catalyst decreases to 64.1% due to inhibited bubble nucleation. A hybrid-wettability coating containing discrete hydrophobic polytetrafluoroethylene (PTFE) domains was developed to facilitate nucleation and hydrogen release. Within the investigated loading range, the 1 wt% PTFE-modified Pd/Al 2 O 3 catalyst achieves the highest hydrogen productivity of 0.547 L H 2 · g ‐ 1 , while the largest relative enhancement of 29.4% over the corresponding γ -Al 2 O 3 reference is obtained at 2 wt% PTFE loading. Thermodynamic analysis confirms that surface wettability is an important interfacial factor regulating the heterogeneous nucleation barrier. This study elucidates the significant influence of bubble nucleation on the H12-NEC dehydrogenation and suggests interfacial wettability engineering as a potentially transferable strategy for gas-evolving LOHC dehydrogenation.