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Highlights: [•] The effect of support on C O hydrogenation and decarbonylation of acyl was studied. [•] The formation of adsorption species from carboxylic acid depended on the nature of support. [•] The presence of enough acid sites and SMSI improved the hydrogenation of acyl species. [•] Decarbonylation of acyl is favored on the bare Ru sites. [ABSTRACT FROM AUTHOR]

The selective hydrogenolysis of 5-hydroxymethylfurfural (HMF) platform molecule to 2,5-dimethylfuran (DMF) has attracted increasing attention due to its broad range of applications. However, HMF, with multiple functional groups, produces various byproducts, hindering its use on an industrial scale. Herein, a bimetallic Pt-FeOx/AC catalyst with low Pt and FeOx loadings for selective HMF hydrogenolysis to DMF was prepared by incipient wetness impregnation. The structures and properties of different catalysts were characterized by XRD, XPS, TEM, ICP-OES and Py-FTIR techniques. The addition of FeOx enhanced Pt dispersion and the Lewis acidic site density of the catalysts, and was found to be able to inhibit C=C hydrogenation, thereby im-proving DMF yield. Moreover, the presence of Pt promoted the reduction of iron oxide, creating a strong interaction between Pt and FeOx. This synergistic effect originated from the activation of the C–O bond over FeOx species followed by hydrogenolysis over the adjacent Pt, and played a critical role in hydrogenolysis of HMF to DMF, achieving a yield of 91% under optimal reaction conditions. However, the leaching of Fe species caused a metal–acid imbalance, which led to an increase in ring hydrogenation products. [ABSTRACT FROM AUTHOR]

• The 5Pt5Fe/C catalyst achieved an exceptional 99.6 % yield in synthesizing 2,5-dimethylfuran from 5-hydroxymethylfurfural. • The 5Pt5Fe/C catalyst efficiently hydrogenated C = O bonds and cleaved C O bonds of diverse substrates. • Ni species in 5Pt5Ni/C leads to a high Ni0 percentage, amplifying hydrogenation activity, leading to the hydrogenation of furan ring. • The 5Pt5Fe/C catalyst demonstrated stable performance, maintaining a commendable DMF yield over five reaction cycles. 2,5-dimethylfuran (DMF), a promising biomass-derived fuel, is synthesized via the hydrodeoxygenation of 5-hydroxymethylfurfural (HMF). This study focuses on the inherent activity of a 5Pt5Fe/C catalyst for HMF hydrodeoxygenation to DMF. The catalyst exhibited exceptional performance, achieving a remarkable DMF yield of 99.6 %. It displayed specific selectivity for C = O bond hydrogenation and C O bond cleavage in diverse substrates, producing high yield of 2-methylfuran from furfural and furfury alcohol, and high yield of toluene from benzaldehyde, benzyl alcohol. In-depth characterizations unveiled valuable insights into the 5Pt5Fe/C catalyst's properties, emphasizing a harmonious balance between metal and acid sites due to the interactive synergy between Pt and Fe species, enhancing hydrodeoxygenation activity. Additionally, the catalyst demonstrated satisfactory stability, maintaining a commendable DMF yield over five reaction cycles despite observed changes. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • A highly dispersed Fe/C catalyst was prepared using pomelo peel as carbon source. • Fe/C catalyst achieved an excellent STY in CO 2 hydrogenation to light olefins. • Metal-support interaction can be regulated by pyrolysis temperature. • Excellent performance is due to the rich functional groups, Fe 3 O 4 and Fe 5 C 2. Although considerable progress has been made in the hydrogenation of CO 2 to light olefins through the modified Fischer-Tropsch synthesis route (CO 2 -FTS), the design of catalysts with high selectivity and stability is still a challenge. Herein, a simple, highly dispersed and scalable Fe/C-400 catalyst was prepared by in-situ pyrolysis using pomelo peel (PP) as carbon source, and was first used in CO 2 hydrogenation to light olefins. This catalyst exhibited a high space time yield of light olefins (48.3 μmol CO2 ·g Fe −1·s−1), and the light olefins selectivity and O/P were 63.0% and 9.0, respectively. More surprisingly, no obvious deactivation was observed within 200 h. A series of characterization techniques such as TEM, TG-MS, FTIR, XPS, H 2 -TPR and 57Fe Mössbauer spectrum showed that the naturally abundant oxygen-containing functional groups in PP support could impart metal-support interactions that enhance the dispersion of iron species. The modulation of the catalyst phase composition was achieved by simply varying the residual amount of oxygen-containing functional groups to impart different metal-support interactions. The catalysts prepared at lower pyrolysis temperatures retained more oxygen-containing functional groups and therefore had stronger metal-support interactions, which facilitated the formation of more active phases. Overall, this newly developed catalyst realized the high activity and high stability production of CO 2 hydrogenation to light olefins, providing a cost-effective and sustainable way for its industrial application. [ABSTRACT FROM AUTHOR]

Acidic promoters are significant in the hydrodeoxygenation (HDO) of bioderived furans into alkanes over metal-acid bifunctional catalysts. Here, a supported Pd/HPW-SiO 2 catalyst was prepared to investigate the promotion effect of phosphotungstic acid (HPW) on the HDO of HMF-acetone adduct (H-Ac). Characterizations suggested that an intimate contact between Pd and HPW was established in Pd/HPW-SiO 2. HPW promoters significantly reduced the reduction temperature of Pd oxides with enhanced hydrogenation and HDO capability. Particularly, in-situ DRIFTS confirmed that Pd-HPW sites significantly weakened the π CO η 2 adsorption mode (ν 3 (C=O)) of C=O group on Pd surfaces. Thereby, the HDO efficiency was synergistically improved through releasing more Pd metal sites to activate hydrogen for hydrogenation and HDO with HPW promoters. Eventually, >90% yield of nonane was efficiently achieved at 160 °C. This work is applicable to explore the structure-activity relationship of bifunctional catalysts in the efficient HDO of complicated oxygenated bioderived furans. • More than 90 % yield of nonane was efficiently obtained from H-Ac at 160 °C. • HPW promoters facilitated Pd oxides to be reduced at 14–40 °C with enhanced hydrogenation and HDO capability. • Pd-HPW sites synergistically improved the HDO efficiency of C-O through weakening the π CO η 2 adsorption mode on Pd sites. [ABSTRACT FROM AUTHOR]

Selective hydrogenation of unsaturated-organic compounds derived from biomass sources is a key step for producing chemicals and fuels, but it faces challenges in enhancing product selectivity and energy efficiency. Metal nanoparticles (NPs) encapsulated in zeolite crystals (metal@zeolite) are desirable and robust materials that can control catalytic activity and selectivity by tuning their structure. However, the solvent effect on selective hydrogenation over metal@zeolite has been unexplored, which plays a significant role in the reaction process. Here, the solvent effect on the selective hydrogenation of cinnamaldehyde (CAL), a representative substrate, over Pd–Ni bimetallic clusters encapsulated inside S-1 zeolite (Pd0.6Ni@S-1) was first reported. The results showed that Pd0.6Ni@S-1 effectively converted CAL into hydrocinnamaldehyde (HCAL) under mild conditions and that the product distribution was solvent-dependent by correlating the selectivity with solvent properties. The polarity of polar solvents affected the solvent-CAL interaction and thus the hydrogenation pathway. Our study reveals the importance of solvent engineering for selective hydrogenation over metal@zeolite catalysts and provides insights for designing efficient and robust materials for biomass conversion. [Display omitted] • Pd0.6Ni@S-1 showed high activity and selectivity for the selective hydrogenation of CAL to HCAL under mild conditions. • The hydrogenation of the C O bond of HCAL was difficult, and the main by-product HCOL was derived from COL. • Conversion and selectivity were controlled by steric effect and polarity of solvent. • Solvent engineering was a key factor in optimizing the performance of metal@zeolite catalysts. [ABSTRACT FROM AUTHOR]

Selective hydrogenation of alkynes is a challenging reaction that requires selective and efficient catalysts to achieve the desired alkenes. The development of general and robust catalysts that can operate under mild conditions and tolerate a wide range of functional groups is still an active area of research. Here, Pd-M bimetallic clusters (M = Ni, Cu, Mn, Fe) encapsulated inside S-1 zeolite were prepared and applied in the selective hydrogenation of substituted terminal alkynes. Among them, the Pd0.6Ni@S-1 catalyst displayed 91 % selectivity to styrene at the full conversion of phenylacetylene. Derivatives of phenylacetylene containing either electron withdrawing/donating or sensitive functional groups were effectively converted into the corresponding alkenes. The confinement effect of zeolite effectively inhibited the over-hydrogenation reaction and enhanced the stability of the catalysts. Furthermore, the product distribution was solvent-dependent by correlating the reaction selectivity with solvent properties. Apolar solvent showed the highest selectivity to styrene in the selective hydrogenation of phenylacetylene due to the competitive adsorption of apolar solvent and styrene on catalysts. [Display omitted] • Pd0.6Ni@S-1: Selective and stable for the selective hydrogenation of terminal alkynes. • The zeolite confinement effect inhibited over-hydrogenation and stabilized metal species. • Solvent affected product distribution, apolar solvents favor styrene formation. • The study reveals solvent effect and metal-zeolite interactions in alkyne hydrogenation. [ABSTRACT FROM AUTHOR]

Direct HDO process for difurfurylidene acetone dimer (F 2 A) conversion to liquid alkanes (C 8 C 14 ) at 260 °C in a batch reactor was investigated over different material supported 1 wt%Pt catalysts, including SAPO-11, HZSM-5, SiO 2 Al 2 O 3 , MCM-22, and home-made SiO 2 ZrO 2 . C 8 C 14 alkanes of 55.8% was obtained over the optimized 1 wt%Pt/SiO 2 ZrO 2 due to its proper pore size of 9.0 nm and moderate acidic centers, together with more than 10% carbon yield of the oxygenated hydrocarbons, including C 11 C 13 chain alcohols & ketones and the hydrogenated F 2 A dimers with furan ring (H-F 2 A dimers). To improve the liquid alkane yield, a two-step process for F 2 A conversion was also investigated, which included low-temperature hydrogenation at 50 °C over Raney Ni catalyst in a batch reactor and the subsequent high-temperature hydrodeoxygenation (HDO) at 280 °C over 1 wt%Pt/SiO 2 ZrO 2 in a fixed-bed reactor. The selectivity of 1,5-di(tetrahydro-2-furanyl)-3-pentanol (II-c) was the highest of 83.0% among the hydrogenated intermediates of H-F 2 A dimers due to the protonation effect of methanol as the solvent and the hydrogenation of C C bonds by Ni active centers. In the same time, the high content of this saturated alcohol H-dimer of II-C increased the solubility and stability of the intermediates in methanol solvent. High carbon yield of C 8 C 14 alkanes of 82.9%(mol) was obtained after oxygen atom removal from H-F 2 A dimers via. the second-step HDO reaction. Long time operation showed the stability of 1 wt%Pt/SiO 2 ZrO 2 as HDO catalyst, deduced from the steady phase structure, acidity of SiO 2 ZrO 2 support and Pt active centers by catalyst characterization. [ABSTRACT FROM AUTHOR]

In this work, Ni-based catalysts were prepared using the impregnation method. Ni/Al 2 O 3 showed good performance with a γ‐valerolactone (GVL) yield of 99.2% from hydrogenation of levulinic acid (LA). Among the tested bimetallic catalysts, the NiCo catalyst showed better performance than NiMn, NiMo, and NiCu catalysts for the hydrogenation of LA to GVL. Catalysts with different Ni/Co ratio were synthesized, and 15%Ni-15%Co/Al 2 O 3 shows the best performance with a GVL yield of 99.5%. The textural and chemical characteristics of the NiCo/Al 2 O 3 were determined by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and H 2 temperature-programmed reduction (H 2 -TPD). This study shows that the incorporation of the Ni and Co metals formed a Ni-Co alloy, which significantly increased the activity than other Ni-based bimetallic catalysts and led to a milder condition for hydrogenation of LA to GVL. The test of reuse potential of 15%Ni-15%Co/Al 2 O 3 exhibited good stability up to 5 cycles without obvious deactivation. • Ni nanodendrites HER catalyst is fabricated via the low-temperature method. • Low overpotential of Ni NDs50 is 49 mV at 10 mA cm−2. • The magnetic anisotropy of nickel nanoparticles benefits to dendrite structure. • Multiple branching dendrite structures provide large electrochemical surface areas for HER. Selective hydrogenation of levulinic acid to γ-Valerolactone over Ni and NiCo catalysts [Display omitted] [ABSTRACT FROM AUTHOR]