Synthesis, characterization and application of pure and decorated with palladium mesoporous cobalt hydroxide hexagonal nanorings

For most of the catalytic reactions dealing with noble metals, a replacement of pure noble metals with hybrid noble metal-nanomaterials or nanocomposites is a well-stablished strategy for reducing the cost of the catalytic process. The application of this strategy is challenging and of interest for the scientific community. In this context, we report the design of Pd-anchored mesoporous cobalt hydroxide nanoring composites which, used as catalysts, can efficiently catalyze Suzuki C–C coupling reactions with excellent activity, versatility and selectivity due to the strong synergetic effect standing from its structure and composition. Hybrid systems based on mesoporous Co(OH)2 nanoparticles and Pd are able to reach up to 88% conversion of iodobenzene and 37% yield of the biphenyl product at 24 h. Additionally, the photocatalytic performance of the hybrid system has been investigated in selective oxidation of benzylalcohol and organic dye degradation. This nanostructured material was able to selectively photo-oxidize benzyl alcohol to benzaldehyde under LED light with moderate catalytic activity (turnover numbers and turnover frequencies were of 4.62 and 0.78 h−1 respectively with 95% selectivity). In addition, the studied hybrid system was able to degrade methylene blue in water with good performance via a photocatalytic reaction by irradiation with UV light and LED light (the kinetic constant for a first order degradation was 1.03·10−4 s−1 and 1.24·10−5 s−1, respectively). Thus, our preliminary catalytic results show that these nanomaterials, based on Co(OH)2 nanoparticles with low content of noble-metal, are promising candidates for their potential use in different industrial catalytic applications.