The development of high-efficient and economical catalysts is a challenging problem for the utilization of sustainable hydrogen energy. Alloying noble metal with non-noble metal is a promising strategy to achieve high catalytic activity and stability of catalysts. Herein, highly dispersed Ru-Cu alloy nanoparticles were successfully fabricated via solid-surfaces-organic-pyrolysis on N-doped carbon coating TiO2 towards hydrogen evolution in NH3BH3 hydrolysis. Ru-Cu alloys with various molar ratios exhibit markedly enhanced catalytic activity than monometallic counterparts. The optimized Ru0.6Cu0.4/TiO2@C-N catalyst achieves an excellent TOF of 626 molH2 molRu−1 min−1 at room temperature. Experimental analysis and DFT calculation reveal the existence of ensemble-boosting effect between Ru and Cu. Multiatomic active sites in alloy significantly promote hydrogen evolution in NH3BH3 hydrolysis. This research provides further understanding of catalytic mechanism and the rational design of high-efficient and economical bimetallic nanocatalysts.

Ensemble-boosting effect of Ru-Cu alloy on catalytic activity towards hydrogen evolution in ammonia borane hydrolysis

Sparked by natural photosynthesis, solar photocatalysis using metal‐free graphitic carbon nitride (g‐C3N4) with appealing electronic structure has turned up as the most captivating technique to the quest for sustainable energy generation and pollution‐free environment. Nonetheless, low‐dimensional g‐C3N4 is thwarted from sluggish kinetics and rapid recombination of photogenerated carriers upon light irradiation. Among multifarious modification strategies, engineering 2D cocatalysts is anticipated to accelerate redox kinetics, augment active sites and ameliorate electron–hole separation of 2D g‐C3N4 for boosted activity thanks to its face‐to‐face contact surface. It is of timely and technological significance to review the 2D/2D interfaces with state‐of‐the‐art 2D cocatalysts, spanning from carbon‐containing to phosphorus‐containing, metal dichalcogenide, and other cocatalysts. Fundamental principles for each photocatalytic application will be introduced. Thereafter, the recent advances of 2D/2D cocatalyst‐mediated g‐C3N4 systems will be critically evaluated based on their interfacial engineering, emerging roles, and impacts toward stability and catalytic efficiency. Importantly, mechanistic insights into the charge dynamics and structure–performance relationship will be deciphered. Last, noteworthy research directions are prospected to deliver insightful ideas for future development of g‐C3N4. Overall, this review is anticipated to serve as a scaffold and cornerstone in designing dimensionality‐dependent 2D cocatalyst‐assisted g‐C3N4 toward renewable energy and ecologically green environment.

Tailor‐Engineered 2D Cocatalysts: Harnessing Electron–Hole Redox Center of 2D g‐C3N4 Photocatalysts toward Solar‐to‐Chemical Conversion and Environmental Purification

Hydrogen generation of ammonia borane hydrolysis catalyzed by Fe22@Co58 core-shell structure

Universal low-temperature oxidative thermal redispersion strategy for green and sustainable fabrication of oxygen-rich carbons anchored metal nanoparticles for hydrogen evolution reactions

Air-engaged fabrication of nitrogen-doped carbon skeleton as an excellent platform for ultrafine well-dispersed RuNi alloy nanoparticles toward efficient hydrolysis of ammonia borane

The central task in efficient heterogeneous catalysis process lies in exploring catalysts with simultaneous superior performance and low cost. The construction of active sites based on low content of noble and non-noble metals is regard as a promising but challenging strategy for the rational design of catalysts. Herein, we report that a NiRu alloy anchored on surface of nitrogen-doped carbon-coated titanium dioxide showed the highest catalytic activity (2.51 × 105 mL·min−1·gRu−1) for NH3BH3 hydrolysis at 298 K. The unprecedented activity is beyond previous reports. The alloy effect in NiRu alloy and the metal-support interaction between alloy and composite support tune the surface d charge. From experimental and DFT simulation results, the optimized surface d charge is positively corresponding to the low active energy in water and ammonia borane molecule activation. This study opens up a new way for the rational design of highly effective non-noble metal heterogeneous catalysts.

Tuning surface d charge of Ni-Ru alloys for unprecedented catalytic activity towards hydrogen generation from ammonia borane hydrolysis

Hydrogen is a potential clean energy carrier for renewable energy sources. The development of high-efficiency and economical catalysts for hydrogen generation is of great importance. In this work, highly dispersed RuFe alloys were prepared and anchored on the surface of microsphere-type N-doped carbon through a facile impregnation-co-reduction process. The spherical N-doped carbon derived from a resorcinol–formaldehyde resin effectively promoted the surface dispersion of the RuFe alloys and the distribution of catalytic active sites on the support surface. According to the density functional theory simulation, the significant positive synergistic effect originated from the coexistence of Ru and Fe in the alloy and effectively reduced the reaction energy barrier. The alloys with various Ru/Fe ratios were more catalytically active for ammonia borane hydrolysis than their supported single Ru or Fe counterparts. This alloy strategy also effectively improved the utilization ratio and stability of Ru. With the optimized Ru2Fe1/N–C catalyst, an unprecedented hydrogen generation specific rate of 9.4 × 104 mL min−1 gRu−1 was achieved at 298 K. The catalytic activity tended to be stable after five consecutive uses. This work provides a beneficial reference for the design of high-efficiency catalysts for hydrogen generation.

Xiaoyan Huang

Papers

Ensemble-boosting effect of Ru-Cu alloy on catalytic activity towards hydrogen evolution in ammonia borane hydrolysis

Tuning surface d charge of Ni-Ru alloys for unprecedented catalytic activity towards hydrogen generation from ammonia borane hydrolysis

Ru–Fe nanoalloys supported on N-doped carbon as efficient catalysts for hydrogen generation from ammonia borane