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The selective hydrogenation of the biomass platform molecule furfural (FAL) to produce furfuryl alcohol (FA) is of great significance to alleviate the energy crisis. Cu-based catalysts are the most commonly used catalysts, and their catalytic performance can be optimized by changing the preparation method. This paper emphasized the effect of calcination atmosphere on the performance of a Cu/Al2O3 catalyst for the selective hydrogenation of FAL. The precursor of the Cu/Al2O3 catalyst prepared by the ammonia evaporation method was treated with different calcination atmospheres (N2 and air). On the basis of the combined results from the characterizations using in situ XRD, TEM, N2O titration, H2-TPR and XPS, the Cu/Al2O3 catalyst calcined in the N2 atmosphere was more favorable for the dispersion and reduction of Cu species and the reduction process could produce more Cu+ and Cu0 species, which facilitated the selective hydrogenation of FAL to FA. The experimental results showed that the N2 calcination atmosphere improved the FAL conversion and FA selectivity, and the FAL conversion was further increased after reduction. Cu/Al2O3-N2-R exhibited the outstanding performance, with a high yield of 99.9% of FA after 2 h at 120 °C and an H2 pressure of 1 MPa. This work provides a simple, efficient and economic method to improve the C=O hydrogenation performance of Cu-based catalysts. [ABSTRACT FROM AUTHOR]

Ni supported on the ordered mesoporous Ce x Zr 1−x O 2 with various Ce/Zr molar ratios prepared by a programmed evaporation-induced self-assembly method were employed for dry reforming of methane. The systematical techniques, including X-ray diffraction, N 2 physisorption, Raman, transmission electron microscope, chemisorption, X-ray photoelectron spectroscopy, diffuse reflection Fourier transform infrared spectrum, thermogravimetric analysis, etc. were used to clarify the structure-activity relationship. It was found that the prepared catalysts all had highly ordered mesoporous structures, and compared to the sole ZrO 2 and CeO 2 , the CeO 2 -ZrO 2 composites exhibited the best thermal stability, stronger basicity, and greater oxygen migration. Especially, the composite with Ce/Zr ratio of 1/4 possessed the suitable basicity and most oxygen vacancies, which were closely related to the excellent anti-carbon ability. Moreover, its supported catalyst had the strongest metal-support interaction and highest Ni dispersion. Expectedly, the catalyst showed the superior activity and the robust stability for at least 1800 min [Display omitted] • Ce x Zr 1−x O 2 were prepared by programmed evaporation-induced self-assembly method. • Composites had higher thermal stability, stronger basicity, greater oxygen migration. • C1Z4 possessed suitable basicity, most oxygen vacancies, highest anti-carbon ability. • NC1Z4 showed the superior activity and the long-term stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • The added Y could enhance metal-support interaction and improve Ni dispersion. • With increasing Y content, surface oxygen species promoting CO 2 activation enriched. • Ni/Y 2 O 3 catalyst exhibited the superior performance and the active carbon deposition. • Pathways of CH 4 dissociation and CO 2 activation were explored by in situ techniques. • Bicarbonate species were reactive intermediates that could become CO and carbonates. Dry reforming of methane is an alternative route to realize the efficient recycling of carbon resources. This work aims to unravel the effects of the Y/Zr molar ratio in the Y 2 O 3 -ZrO 2 supports on metal-support interaction (MSI) and surface oxygen species, where the former is related to Ni dispersion and the anti-sintering ability and the latter is corresponded to CO 2 activation and anti-carbon deposition ability. Interestingly, the characterization results reveal that increasing Y content in the catalyst effectively enhances MSI, improves Ni dispersion, and enriches the surface oxygen species. Also, the higher Y content in the catalyst makes carbon deposition more active and easier to be removed, and the nature of carbon deposition, rather than the amount, is the crucial factor for catalyst deactivation. As a result, the catalyst with high Y content shows the superior performance. Specially, Ni/Y 2 O 3 exhibits the highest CH 4 and CO 2 conversion (∼80 % and 85 %, respectively) among the representative catalysts at 700 °C, and its activity (CH 4 conversion: ∼88 %, CO 2 conversion: ∼93 %) can maintain at least 3600 min at 750 °C. Moreover, the origin of the excellent performance over the catalyst with high Y content is elucidated and the reaction mechanisms are discussed using in situ experiment techniques. The metallic Ni species are active sites to dissociate CH 4 and the oxygen species react with the carbonaceous species derived from CH 4 cracking to produce CO or CO 2. After consuming the adsorbed oxygen species, the re-exposed oxygen vacancies and hydroxyl groups adsorb CO 2 to form the active intermediates again, including the bicarbonate and carbonate species. Furthermore, the bicarbonate species are verified to be more active than the other carbonates, and they can react with the carbonaceous species to produce CO or transform into the carbonates. [ABSTRACT FROM AUTHOR]