TiO2 inserted carbon materials with fine-tuned pore structure as effective model supports for electrocatalysts of fuel cells

Commercially available carbon black is a widely applied support material for nanocatalysts but notorious for its microporous structure, which is deleterious for catalysts utilization in the fuel cell application and causes numerable problems in other application areas. The development of mesoporous carbon as a substitute was proved successful but not scalable due to their intrinsic complex synthesis. In this work, we demonstrate a new perspective to circumvent the problem through blocking the micropores of carbon black by the in-situ formed TiO2 nano/sub-nano particles. A decompression absorption method was developed where tetrabutyl titanate was pressurized into carbon pores with diameter <3 nm, succeeded by hydrolysis and calcination to form the TiO2 inserted commercial carbon black, such as BP2000 and Vulcan XC-72. The TiO2-C hybrid material with reduced micropore volume was found an excellent support for noble catalysts, such as Pt and Pd nanoparticles, where their insertion into carbon micropores during synthesis were prevented, thus leading to improved metal utilization. The TiO2-C supported catalysts exhibited much superior activity and stability for methanol or formic acid electrooxidation in comparison to the plain carbon black. This work also demonstrated the negative effects of micropores in carbon support.