Atomic scale niobium implantation in dealuminated industrial H-β zeolite catalyst for enhanced furfural production

To develop an industrial zeolite-based catalyst for efficient furfural production, the acidity, pore structure, and electronic properties of H-β zeolite were modulated by synergistic deatomization and atomic implantation treatments. The dealumination effectively decreased the intrinsic aluminum-related Lewis and Brosted acid sites, thus decreasing the occurrence of unwanted side reactions. Meanwhile, the removed skeleton aluminum can create voids for the following atomic implantation of introducing higher valent-state niobium species, which would provide new kinds of catalytic active sites, increase the average pore size by distorting the zeolite skeleton, and enhance the interaction with reactant molecules by acting as more electron deficient centers. In a single-phase water/γ-valerolactone reaction system, the optimum catalyst can efficiently convert both xylan and xylose with a conversion of 100 % at a medium temperature of 130 ℃ within 3 hours. Compared with the furfural yield over untreated H-β (12.7%), the yield over deAlβ/Nb(20%) catalyst was greatly enhanced by 54% with xylose as raw material. The catalyst can be recovered by simple cleaning and thermal regeneration and then reused. The proposed post-treatment strategy could maintain the integrity of the zeolite structure, ensure uniform and stable metal dispersion under harsh conditions, manage the complexity and cost of the preparation process, and most importantly, optimize the catalytic performance. Addressing these issues is essential for improving the efficiency and practical application of industrial zeolite catalysts by this general approach and benefiting industrial furfural production.