Reactant Concentrations-Mediated Void-Confinement Effects of TMPs@HCs Nanoreactors for Biomass Hydrodeoxygenation

As a promising renewable energy, biomass has great potential in producing value-added chemicals and biofuels. Pyrolysis is the most promising method to convert biomass into bio-oil. However, the high oxygen content of bio-oil leads to its unstable performance, which requires further processing to meet the use requirements. Hydrodeoxygenation (HDO) is an effective strategy to efficiently upgrade bio-oil by selectively removing oxygen-containing functional groups. However, the traditional HDO catalyst has some problems, such as easy coking and deactivation, low yield of target products, and so on. Therefore, it is of great significance to construct a high-performance HDO catalyst and reaction system to realize efficient conversion of biomass. Hollow nanoreactors have attracted considerable attention in the field of catalysis due to their void-confinement effect and high efficiency. In this study, we prepared loaded Ni2P/HCs-0.25 and encapsulated Ni2P@HCs-x with different cavity sizes based on the soft template method and found that the metal location (inside and outside) and cavity size have a great influence on the void-confinement effect of different reactant concentrations. Due to the enrichment effect of reactant concentration and electron metal–support interaction, Ni2P@HCs-x with different cavity sizes showed different degrees of void-confinement effects, the larger the cavity, the more significant the void-confinement effects on different concentrations of reactants, and under the quantitative catalyst and optimal reaction conditions, [email protected] showed excellent void-confinement effects to achieve the optimal catalytic effect of vanillin concentration up to 20%. In fact, the cavity as a site for reactant aggregation can locally increase the concentration of reactants within the cavity, but only a nanoreactor with a suitable cavity size can exhibit the optimal void-confinement effect and show excellent catalytic performance. This work not only provides insight into the void-confinement effect of hollow nanoreactors on concentration but also provides valuable strategies to improve the efficient conversion of biomass.