Ultrahigh Metal Content Carbon-Based Catalyst for Efficient Hydrogenation of Furfural: The Regulatory Effect of Glycerol

Abstract

The development of high-content non-noble metal nanocatalysts is important for multiphase catalysis applications. However, it is a challenge to solve the agglomeration in the preparation of high-content metal catalysts. In this paper, a carbon-based catalyst (Co@CN-G-600) with 71.28 wt % cobalt metal content was prepared using a new strategy of gas-phase carbon coating assisted by glycerol. The core of this strategy is to maintain the spacing of metallic cobalt by continuous replenishment of dissociated ligands during pyrolysis over gas-phase glycerol. This approach is also applicable to other non-noble metals. When Co@CN-G-600 was further used as a catalyst for the selective hydrogenation of furfural (FF) to prepare furfuryl alcohol (FOL), the yield of FOL was >99.9% under mild conditions of 80 °C, compared to only 8.23% catalytic yield at up to 130 °C for Co@CN-600 without glycerol. The excellent catalytic performance mainly lies in the fact that the introduction of glycerol modulates the size effect, electronic effect, and acidic site intensity of the high-content Co catalyst, which promotes the activation of FF and hydrogen. Meanwhile, the optimized specific surface area and pore structure by glycerol improve the accessibility of high-density active sites and promote more efficient mass transfer. In addition, the introduction of glycerol produced a graphitic carbon layer encapsulation structure relative to Co@CN-600, which substantially improved the cycling stability of the catalyst. This study resolves the paradox of high content and high dispersion of non-noble metal catalysts in the synthesis process and provides a general pathway and example for the preparation of stable high-content metal catalysts.

Composition control of Pd-based bimetallic alloys to boost selective hydrogenation of furfural in aqueous micelles

“…As expected, palladium catalyst or nickel catalyst alone was unable to effectively generate the target product THFA (Table S1, † entries 4 and 5). A series of PdNi alloy catalysts with different metal compositions were synthesized by co-reduction using NiCl 2 and Na 2 PdCl 4 as precursors with sodium borohydride, further achieving the corresponding hydrogenation products (Table 1, entries [13][14][15][16][17]. Herein, the Pd 1 Ni 3 alloy exhibited optimal catalytic performance with a yield of 95.6% and a selectivity of 96.2% for THFA.…”

“…[12][13][14] There are two general approaches to designing catalysts for selective hydrogenation: the construction of multimetallic catalysts and the surface modification of metal nanoparticles. 15,16 For example, in traditional industries, the Cu-Cr catalyst (CuCrO x ) is well developed to catalyze selective hydrogenation of FF to FA, but the toxicity of Cr can cause serious product contamination problems. 17 Therefore, a number of environmentally friendly metal catalysts, e.g., Pd, Ni, Co and Fe, have been employed as alternatives to the Cr component.…”