Dual activation pathways based on OH-functionalized alk-Ti3C2 MXene/RuOx boosting the hydrogen generation

Abstract

A meticulous design of the local environment at the interface between active species and the support, aimed at optimizing the adsorption of H₂O molecules and BH₄⁻ anion, offers an ideal strategy for enhancing hydrogen generation via NaBH₄ hydrolysis through dual activation pathways. Theoretical predictions based on d-band center analysis and electron transfer calculations suggest that introducing -OH functional groups induce charge redistribution, enhancing charge concentration on alk-Ti₃C₂ and facilitating the adsorption and activation of dual active species, H₂O molecules and BH₄⁻ anion. Inspired by these predictions, the optimized alk-Ti₃C₂/RuO_x catalyst demonstrates the highest catalytic activity, achieving a hydrogen generation rate (HGR) of 9468 mL min⁻¹ g_cat.⁻¹. Both experimental data and theoretical analyses confirm that the -OH functional groups promote charge enrichment on alk-Ti₃C₂, optimizing the adsorption of H₂O molecules and BH₄⁻ anion, and reducing the dissociation energy barrier of the *OHH-TS intermediate. This dual activation pathways mechanism lowers the activation energy for NaBH₄ hydrolysis, significantly enhancing the HGR performance. These findings, guided by theoretical insights, establish alk-Ti₃C₂/RuO_x as an efficient catalyst for NaBH₄ hydrolysis and provide a strong foundation for future hydrogen generation catalyst designs.