Ultrafast joule-heating-assisted O, N dual-doping of unfunctionalized carbon enhances Ru nanoparticle-catalyzed hydrogen production

The development of a rapid and convenient strategy to regulate the surface microenvironment of inert carbon supports, along with the physicochemical properties of their supported metal nanoparticles, is essential for enhancing catalytic performance. In this study, we describe a straightforward and efficient solid-state microwave method that utilizes a household microwave oven to achieve the co-doping of oxygen and nitrogen in unfunctionalized carbon black (ONCB) using urea as a nitrogen source. The microwave solid-state treatment of commercial carbon black (CB) with urea not only introduces a significant number of heteroatomic functional groups but also substantially increases the pore size and pore volume of the matrix. These enhancements facilitate the uniform growth and dispersion of ultrafine Ru nanoparticles on the surface of ONCB. Consequently, the Ru/ONCB catalyst provides abundant catalytic active sites and mass transfer channels, thereby improving catalytic performance for hydrogen evolution from ammonia borane hydrolysis (ABH). The turnover frequency of Ru/ONCB for ABH reaches 4529 ± 238 min^-1 (determined based on Ru dispersion), surpassing a range of analogues and many previously reported carbon-supported Ru catalysts. This study presents a simple and rapid strategy to regulate the surface microenvironment of unfunctionalized carbon support, thereby enhancing the catalytic performance of its supported metal nanoparticles for catalytic hydrogen generation.