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Increasing selectivity without the expense of activity is desired but challenging in heterogeneous catalysis. By revealing the molecule saturation and adsorption sensitivity on overlayer thickness, strain, and coordination of Pd‐based catalysts from first‐principles calculations, we designed a stable Pd monolayer (ML) catalyst on a Ru terrace to boost both activity and selectivity of acetylene semihydrogenation. The least saturated molecule is most sensitive to the change in catalyst electronic and geometric properties. By simultaneously compressing the Pd ML and exposing the high coordination sites, the adsorption of more saturated ethylene is considerably weakened to facilitate the desorption for high selectivity. The even stronger weakening to the least saturated acetylene drives its hydrogenation such that it is more exothermic, thereby boosting the activity. Tailoring the molecule saturation and its sensitivity to structure and composition provides a tool for rational design of efficient catalysts. [ABSTRACT FROM AUTHOR]

Semi‐hydrogenation of acetylene to ethylene is an important process to purify ethylene streams in industry. However, among current approaches reported in the literature, high ethylene selectivity has been generally achieved at the expense of activity. Herein, we show that a Ga2O3 coating of Ag@Pd core–shell bimetallic nanoparticle catalysts, allows improvement of the ethylene selectivity to a much greater extent than the coating of monometallic Pd nanoparticles, while preserving a remarkable intrinsic activity, approximately 50 times higher than the benchmark catalyst of Pd1Ag single‐atom alloys (SAAs). Importantly, the resulting catalyst also shows excellent long‐term stability, by suppressing coke formation efficiently. Spectroscopic characterization reveals that weakened ethylene adsorption by bimetallic electronic synergy, and oxide site isolation are both essential for the high ethylene selectivity and high‐coking resistance. H‐D exchange measurements further show that the Ga2O3‐coated Ag@Pd catalyst possesses a much higher activity of H2 activation than that of Pd1Ag SAAs, thus boosting the hydrogenation activity at the same time. [ABSTRACT FROM AUTHOR]

In this work, a core-shell-like sphere ruthenium catalyst, named as 5%Ru/γ-Al2O3@ASMA, has been successfully synthesized through impregnating the ruthenium nanoparticles (NPs) on the surface of the amino poly (styrene-co-maleic) polymer (ASMA) encapsulating γ-Al2O3 pellet support. The interaction between the Ru cations and the electro-donating polymer shell rich in hydroxyl and amino groups through the coordination bond would guarantee that the Ru NPs can be highly dispersed and firmly embedded on the surface of the support. In addition, the solid sphere γ-Al2O3 pellet could serve as the core to support the resulted catalysts applied in the flow process in a trickle bed reactor to promote the productivity. The resulted catalyst 5%Ru/γ-Al2O3@ASMA can be applied efficiently in the glucose hydrogenation and presents a steadfast sorbitol yield of almost 90% both in batch reactor and the trickle bed reactor, indicating the potential feasibility of the core-shell-like catalyst in the efficient production of sorbitol. [ABSTRACT FROM AUTHOR]

• Enzyme-like catalyst S/CuMgAL-41 with confined space was successfully constructed by coprecipitation and thiourea modification. • The S/CuMgAl-41 is a bifunctional catalyst with both acidic and alkaline active site. • NO 3 2− and SO 4 2− come from calcination of CuMgAL-41 modified by thiourea not only enhance the electrophilicity of aldehydes but also anchor of p -NBD with NO 3 2− and SO 4 2− by hydrogen, thereby increase the selectivity of the entantiomers and ee value. • The asymmetric aldol addition of p -NBD with acetone catalyzed S/CuMgAL-41 is the synergistic result of diverse factors such as the acid-base active center on the S/CuMgAL-41, hydrogen bonding, confined effect, anchoring effect. In this study, a series catalysts of CuMgAl-LDHs were successfully prepared by co-precipitation method. Subsequently, the catalyst S/CuMgAl-41 was prepared by modifying CuMgAl-41 with thiourea. The physical and chemical properties of the catalyst were characterized by XRD, N 2 adsorption-desorption, SEM, ICP, FT-IR, TG-DSC and XPS. The catalytic performance of the catalyst was investigated. It showed that S/CuMgAl-41 exhibited synergistic catalytic activity with better ee value due to both acidic and alkaline active sites and confined spaces with proper interlayer spacing. When isopropyl alcohol was chosen as solvent, the S/CuMgAl-41 has the best catalytic effect for asymmetric aldol addition reaction between p -nitrobenzaldehyde (p -NBD) and acetone. Additionally, the process conditions for optimizing the asymmetric addition reaction have been thoroughly studied. It was found that S/CuMgAl-41 exhibited good reusability and stability. Moreover, the asymmetric aldol addition of acetone and p -NBD catalyzed by S/CuMgAL-41 can occur due to the result of synergistic effects of various factors, including acid-base active center, hydrogen bond, confined effect and anchoring effects between hydrotalcite laminate of S/CuMgAL-41. This novel catalytic design provides a new idea for asymmetric synthesis of p -NBD and acetone. In this study, a series catalysts of CuMgAl-LDHs were successfully prepared by co-precipitation method. Subsequently, the catalyst S/CuMgAl-41 was prepared by modifying CuMgAl-41 with thiourea. The physical and chemical properties of the catalyst were characterized by XRD, N 2 adsorption-desorption, SEM, ICP, FT-IR, TG-DSC and XPS. The catalytic performance of the catalyst was investigated. It showed that S/CuMgAl-41 exhibited synergistic catalytic activity with better ee value due to both acidic and alkaline active sites and confined spaces with proper interlayer spacing. When isopropyl alcohol was chosen as solvent, the S/CuMgAl-41 has the best catalytic effect for asymmetric aldol addition reaction between p -nitrobenzaldehyde (p -NBD) and acetone. Additionally, the process conditions for optimizing the asymmetric addition reaction have been thoroughly studied. It was found that S/CuMgAl-41 exhibited good reusability and stability. Moreover, the asymmetric aldol addition of acetone and p -NBD catalyzed by S/CuMgAL-41 can occur due to the result of synergistic effects of various factors, including acid-base active center, hydrogen bond, confined effect and anchoring effects between hydrotalcite laminate of S/CuMgAL-41. This novel catalytic design provides a new idea for asymmetric synthesis of p -NBD and acetone. [Display omitted] [ABSTRACT FROM AUTHOR]

Trimethylolpropane trioleate (TMPTO), as a bio-lubricant, offers significant advantages over mineral oils, especially in terms of reducing environmental pollution. While produce cost are still the challenges in developing biodegradable lubricants, thereby it's urgent TMP to produce TMPTO economically and environmentally friendly. Herein, a novel shaping catalyst SO 4 2−/SnO 2 -RC was prepared through press tableting and impregnation methods. Molding conditions of catalyst support and preparation process of SO 4 2−/SnO 2 -RC catalyst were investigated in detail. The catalytic materials were characterized by various techniques such as XRD, By-IR of adsorbed pyridine, BET, SEM-EDX, acid-base titration. The prepared catalysts were found to have enough mechanical intensity, acid sites of Brønsted and Lewis, by which the esterification reaction of TMP and oleic acid (OA) was catalyzed synergistically. Furthermore, the shaping catalyst SO 4 2−/SnO 2 -RC was tested in the esterification reaction of TMP and OA to produce TMPTO in the fixed bed reactor. The catalyst presented maximum conversion of 99.7% under optimal reaction conditions such as TMP to OA mole ratio of 1:29, Space velocity of 1.6 h−1 and reaction temperature of 150 °C, and consecutive esterification experiment of 1000 h in fixed bed reactor exhibits excellent stability of, shaping catalyst SO 4 2−/SnO 2 -RC. The current work has clearly demonstrated that esterification reaction of TMP and OA in trickle bed can greatly shorten the reaction time and increase the conversion of TMP. This kind of molding solid acid catalyst has potential applications in industrial catalysis. • A novel shaping catalyst SO 4 2−/SnO 2 -RC was prepared through press tableting and impregnation methods. • Molding conditions of catalyst support and preparation process of SO 4 2−/SnO 2 -RC catalyst were investigated in detail. • The esterification reaction of TMP and oleic acid was catalyzed synergistically by acid sites of Brønsted and Lewis. • The shaping catalyst SO 4 2−/SnO 2 -RC was tested in the esterification reaction of TMP and OA to produce TMPTO in the fixed bed reactor. [ABSTRACT FROM AUTHOR]

[Display omitted] • CuMgAl Layer Double Oxides are prepared under certain amount of copper contents. • The catalyst is applied in the selective hydrogenolysis of furfural to pentanediols. • The catalysis is determined by the synergism between copper and acid-base sites. • The catalytic properties of the catalyst can be maintained after five runs. A series of layer double metal oxides (LDO) from CuMgAl hydrotalcite precursors were prepared by urea decomposition under different calcination temperatures in this work. Various characterizations including XRD, SEM, FTIR, XPS, H 2 -TPR, NH 3 -TPD and CO 2 -TPD were carried out to investigate the structural properties of the as-prepared samples. After calcination at certain temperatures, the resulted LDO presents the excellent catalytic property in the selective hydrogenolysis of furfural (FA) to 1,2-pentanediol (1,2-PeD) and 1,5-pentanediol (1,5-PeD). The Cu+/Cu2+ ratio and the acid-base amount from the calcination process play the key role in the catalytic performance towards this reaction. The optimal catalyst (CuMgAlO-S3) with the maximal Cu+/Cu2+ ratio and the acid-base amount exhibits the best catalytic performance towards hydrogenation of furfural to 1,2-pentanediol (selectivity 55.2 %.) and 1,5-pentanediol (selectivity 28.5 %) with more than 80 % of conversion rate, which indicated the selectivity of 1,2- and 1,5-PeDs counted on the synergistic effect of Cu+ and acid-base properties. [ABSTRACT FROM AUTHOR]