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Biomass‐derived feedstocks play a vital role in sustainable economies for renewable energy, waste management, energy security, and commercial prospects. This study focused on promoting the ring hydrogenation of furfural (FAL) into tetrahydrofurfuryl alcohol (THFA) in an aqueous solution using a potential Ni−Re‐supported hydrotalcite‐derived MgAl catalyst at different Ni : Re molar ratios. Structural analyses, such as an in situ time‐resolved X‐ray absorption near edge structure, under H2 reduction elucidated the simultaneous transformation of Re6+ and Re7+ to Re0 with the remaining highly stable Ni2+. The construction of Ni−Re on hydrotalcite‐derived MgAl catalyst resulted in the alleviated H2 reduction behavior, facilitated H2 adsorption and desorption processes, and suitable catalyst acidity detected by H2 temperature‐programmed reduction, and H2 and NH3 temperature‐programmed desorption experiments, respectively. Under optimized conditions, a maximum THFA yield of 78 % with a complete FAL conversion was attained using Ni1Re0.16/MgO−Al2O3 catalyst at a reaction temperature of 140 °C, H2 pressure of 20 bar, catalyst loading of 20 %, and reaction time of 2 h in a H2O system. Isotopic deuterium (D2O) labeling revealed that D substitution was notably pronounced through isotopic exchange between the D atom from D2O and H atom in FAL during its hydrogenation to THFA. [ABSTRACT FROM AUTHOR]

Selective hydrogenation and hydrogenolysis of 5‐hydroxymethylfurfural (HMF) to 2,5‐bis(hydroxymethyl)furan (BHMF) and 2,5‐dimethylfuran (DMF) were explored by regulating the nanosized Pt on Co/Al2O3 catalysts. Characterization results revealed that the catalyst acidity was influenced by adjusting the Co/Pt composition, while the addition of more Pt loading on Co/Al2O3 catalysts resulted in a facilitation of H2 reduction process. Lower size of catalyst particles was obtained for the Co−Pt system in comparison to the monometallic Co/Al2O3 catalyst. Additionally, the structural characterizations by XRD, XANES, and XPS established the co‐existences between metallic Pt0/Co0 and oxophilic PtO2/CoOx, acting as the active components for the reactions. Operated under a full HMF conversion, the Co1Pt0.050Al catalyst with high Pt loading gave >99.9 % BHMF selectivity at 40 °C; whereas, an 86.7 % of DMF selectivity was noticeable over low Pt loading of the Co1Pt0.013Al catalyst at 160 °C. This investigation evidenced that the selective production of BHMF or DMF towards hydro‐conversion of HMF was relied on the amount of Pt contents on Co/Al2O3 catalyst, in which the metal sizes and acidity had meaningful effects on the hydrogenation and hydrogenolysis processes. [ABSTRACT FROM AUTHOR]

The upgradation of methane in biogas by hydrogenation of CO2 has been currently recognized as a promising route for efficient full utilization of renewable biogas with potential benefits for storage of renewable hydrogen energy and abatement of greenhouse gas emission. As a main constituent of biogas, CO2 can act as a backbone for the formation of additional CH4 by hydrogenation, then producing higher amounts of biomethane. In this work, the upgradation process was investigated in a prototype reactor of double pass operation with vertical alignment using an optimized Ni-Ce/Al-MCM-41 catalyst. The experimental results show that the double pass operation that removes water vapor during the run can significantly increase CO2 conversion, resulting in higher CH4 production yield. As a result, the purity of biomethane increased by 15% higher than a single pass operation. In addition, search for optimum condition of the process was carried out within an investigated range of conditions including flowrate (77–1108 ml min−1), pressure (1 atm–20 bar), and temperature (200–500 °C). The durability test for 458 h was performed using the obtained optimum condition, and it shows that the optimized catalyst can perform excellent stability with negligible influence by the observed change in catalyst properties. The comprehensive characterization on physicochemical properties of fresh and spent catalysts was performed, and the results were discussed. [ABSTRACT FROM AUTHOR]

Cu/CaO catalysts with fine-tuned Co-doping for excellent catalytic performance of furfural (FAL) hydrogenation to furfuryl alcohol (FOL) were synthesized by a facile wetness impregnation method. The optimal Co1.40Cu1/CaO catalyst, with a Co to Cu mole ratio of 1.40:1, exhibited a 100% FAL conversion with a FOL yield of 98.9% at 100 °C and 20 bar H2 pressure after 4 h. As gained from catalyst characterizations, Co addition could facilitate the reducibility of the CoCu system. Metallic Cu, Co-Cu alloys, and oxide species with CaO, acting as the major active components for the reaction, were formed after reduction at 500 °C. Additionally, this combination of Co and Cu elements could result in an improvement of catalyst textures when compared with the bare CaO. Smaller catalyst particles were formed after the addition of Co into Cu species. It was found that the addition of Co to Cu on the CaO support could fine-tune the appropriate acidic and basic sites to boost the FOL yield and selectivity with suppression of undesired products. These observations could confirm that the high efficiency and selectivity are mainly attributed to the synergistic effect between the catalytically active Co-Cu species and the CaO basic sites. Additionally, the FAL conversion and FOL yield insignificantly changed throughout the third consecutive run, confirming a high stability of the developed Co1.40Cu1/CaO catalyst. [ABSTRACT FROM AUTHOR]