Enhanced Metal-Support Interaction in Ni/Co3O4/TiO2 Nanorods toward Stable and Dynamic Hydrogen Production from Phenol Steam Reforming

The fabrication of highly stable Ni and Co3O4 nanocube-supported TiO2 nanorods (NRs) catalysts with improved metal-support interaction for steam reforming of phenol (SRP) has been investigated. An enhanced catalytic performance of Ni/Co3O4/TiO2 NRs with H-2-rich gas and hardly formed coke was achieved and rationalized with spectroscopic results and structural assessments. Over 10% Ni/5% Co3O4/TiO2 NRs, SRP and water gas shift reactions dominate, producing mostly H-2 and CO2, yet Ni/TiO2 microparticles promoted CO. With catalyst loading, steam-to-carbon ratio, and gas hourly space velocity, the H-2 yield was improved with higher CO2/CO ratio and low CO yield. A Ni/Co3O4/TiO2 NRs catalyst possesses excellent stability, which prevailed for more than 100 h without obvious deactivation. The high performance was due to a 1D TiO2 NRs/Co3O4 nanocubes heterojunction, good metal dispersion, and higher reducibility, thereby providing a strong interaction of bimetallic active sites. This study reveals that Co3O4 promotes Ni/TiO2 NRs activity and stability toward H-2 production and is promising for commercial applications.