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Ni/CaO, a low-cost dual-functional material (DFM), has been widely studied for integrated CO[sub.2] capture and hydrogenation. The core of this dual-functional material should possess both good CO[sub.2] capture–conversion performance and structural stability. Here, we synthesized Ni/CaO DFMs modified with alkali metals (Na, K, and Li) through a combination of precipitation and combustion methods. It was found that Na-modified Ni/CaO (Na-Ni/CaO) DFM offered stable CO[sub.2] capture–conversion activity over 20 cycles, with a high CO[sub.2] capture capacity of 10.8 mmol/g and a high CO[sub.2] conversion rate of 60.5% at the same temperature of 650 °C. The enhanced CO[sub.2] capture capacity was attributed to the improved surface basicity of Na-Ni/CaO. In addition, the incorporation of Na into DFMs had a favorable effect on the formation of double salts, which shorten the CO[sub.2] capture and release process and promoted DFM stability by hindering their aggregation and the sintering of DFMs.

Developing highly efficient photocatalysts for CO[sub.2] reduction remains a great challenge. The large band gap and poor charge carrier dynamics are the major factors limiting the performance of Bi[sub.4]Ti[sub.3]O[sub.12] (BTO). Herein, a series of La-doped Bi[sub.4]Ti[sub.3]O[sub.12] (BLa[sub.x]TO) nanosheets were synthesized and further modified by NaBH[sub.4] hydrogenation to create surface defect-rich H-BLa[sub.X]TO nanosheets. Characterizations and theoretical calculations confirmed that the synergistic effect of La doping and hydrogenation significantly enhanced visible-light absorption, promoted charge separation, and improved the electron reduction capacity. When applied to photocatalytic CO[sub.2] reduction, the H-BLa[sub.0.2]TO catalyst achieved a superior CH[sub.3]OH production rate of 7.90 μmol·g[sup.−1]·h[sup.−1], which is 5.6 times higher than that of pristine Bi[sub.4]Ti[sub.3]O[sub.12]. Moreover, the H-BLa[sub.0.2]TO catalyst maintained excellent stability over four consecutive cycles. This study offers an integrated strategy for constructing high-performance bismuth-based photocatalysts through elemental doping and defect engineering.

2-Methyltetrahydrofuran (2-MTHF), a hydrogenated derivative of levulinic acid (LA), is a biomass-derived platform compound with diverse and significant applications as a biofuel, gasoline additive, green solvent, and pharmaceutical synthesis intermediate. This study investigates the preparation of a Cu[sub.1]Ni[sub.2]/Al[sub.2]O[sub.3] catalyst through the calcination–reduction of CuNiAl hydrotalcite as a precursor, which was subsequently utilized in the hydrogenation of LA to produce 2-MTHF. The calcination–reduction process applied to CuNiAl hydrotalcite results in a lattice confinement effect. This method not only disperses the active metal sites but also alters the bonding patterns of the active metals, thereby enhancing the activity and stability of the Cu[sub.1]Ni[sub.2]/Al[sub.2]O[sub.3] catalyst. The results indicate that complete conversion of LA and a 2-MTHF yield of 87.6% can be achieved under optimal conditions of 190 °C, 5 MPa hydrogen, and a reaction time of 5 h, demonstrating an efficient one-step conversion process. Additionally, the catalyst’s recyclability was assessed through multiple reuse tests, with a loss of activity of only 9.2% after six cycle experiments, suggesting its feasibility and reliability for industrial applications.

DRIFTS experiments such as CO adsorption, CO-TPSR and CO+H.sub.2 were designated to study the effect of Fe promoter on the key steps of C.sub.2 oxygenates formation from syngas. The CO adsorption results demonstrated that Fe weakened CO adsorption and especially the bridging adsorption. It was found in CO-TPSR experiments that the catalyst with lower Fe loading is more easily dissociated while the ones with higher Fe loading own stronger hydrogenation activity. Moreover, it was observed by CO+H.sub.2 experiments that Fe plays a role in stabilizing the lineally adsorbed CO species and decreasing the CO desorption rate. The catalytic performance results indicated that when Fe content is 4wt. %, the selectivity of total C.sub.2 oxygenates is the highest, which was in accordance with the DRIFTS results.

Cu/ZnO/CeO.sub.2 nanocomposite was supported on metal organic framework (MOF-5) to enhance active sites dispersion and control the nanoparticles agglomeration during synthesis through strong metal-support interactions. The incorporation of MOF-5 alleviated the obstacle facing the commercial ternary Cu/ZnO/Al.sub.2O.sub.3 regarding low surface area due to nanoparticles agglomeration. In addition, Cu/ZnO/CeO.sub.2@MOF-5 gave higher methanol selectivity than the commercial catalyst which can be accounted for by the interfacial sites generated between MOF-5 and Cu/ZnO which favour methanol synthesis over carbon monoxide through regulating the intermediates bonding energies. CeO.sub.2 as support for Cu/ZnO nanoparticles was also compared with commercial support and showed to have led to smaller particle size and superior dispersion of Cu active sites as well. Cu/ZnO/CeO.sub.2@MOF-5 resulted in methanol STY of 23.3 mg g.sub.cat h.sup.-1 and selectivity of 79% at mild reaction temperature (260 °C) and pressure (10 bar). Two different MOFs including cerium based MOF and ZIF-8 demonstrated inferior performance compared to MOF-5.

Sulfur-protected enantiopure P-chiral 1-phosphanorbornane silyl ethers 5a,b are obtained in high yields via the reaction of the hydroxy group of P-chiral 1-phosphanorbornane alcohol 4 with tert-butyldimethylsilyl chloride (TBDMSCl) and triphenylsilyl chloride (TPSCl). The corresponding optically pure silyl ethers 5a,b are purified via crystallization and fully structurally characterized. Desulfurization with excess Raney nickel gives access to bulky monodentate enantiopure phosphorus(III) 1-phosphanorbornane silyl ethers 6a,b which are subsequently applied as ligands in iridium-catalyzed asymmetric hydrogenation of a prochiral ketone and enamide. Better activity and selectivity were observed in the latter case.

The selective hydrogenation of nitroarenes to N-arylhydroxylamines is an important synthetic process in the chemical industry. It is commonly accomplished by using heterogeneous catalytic systems that contain inhibitors, such as DMSO. Herein, DMAP has been identified as a unique additive for increasing hydrogenation activity and product selectivity (up to >99%) under mild conditions in the Pt/C-catalyzed process. Continuous-flow technology has been explored as an efficient approach toward achieving the selective hydrogenation of nitroarenes to N-arylhydroxylamines. The present flow protocol was applied for a vast substrate scope and was found to be compatible with a wide range of functional groups, such as electron-donating groups, carbonyl, and various halogens. Further studies were attempted to show that the improvement in the catalytic activity and selectivity benefited from the dual functions of DMAP; namely, the heterolytic H[sub.2] cleavage and competitive adsorption.

The synthesis of C.sub.2 oxygenates including ethanol directly from coal-derived syngas is significant from both academic and practical points of view and SiO.sub.2 supported Rh-based catalysts are very effective for this conversion. However, the high price of Rh requires the improvement of its dispersion to maximize Rh efficiency. The adjustment of impregnation solution pH value can modify effectively the metal dispersion over the support. Herein, we reported the pH effect on catalytic performance of Rh-Mn-Li/SiO.sub.2 for CO hydrogenation to C.sub.2 oxygenates for the first time. A series of catalysts were prepared from different pH values of impregnation solutions, and were characterized by various techniques. With the increasing of solution pH value above zero point of charge (ZPC) of silica, Rh particle sizes increased with much wider size distribution and reduction of Rh species was restrained over the prepared catalysts owing to the stronger interaction between Rh and support. As a result, the active sites for CO insertion, especially for CO or H.sub.2 dissociation was lowered, leading to the depletion of the activity for the formation of C.sub.2 oxygenates from CO hydrogenation, and larger Rh particle size with wider size distribution favors the production of long chain hydrocarbons. On the contrary, when the catalyst was prepared using solution with pH below ZPC of silica, the dispersion and the reduction of Rh were promoted due to suitable Rh-support interaction, and in the CO hydrogenation reaction, the space time yield and selectivity of C.sub.2 oxygenates reached 679.4 g/kg-cat/h and 73.3%, respectively.

The mechanically alloyed amorphous alloys of the Ti[sub.45]Zr[sub.38]Ni[sub.17] composition are known for their ability to form a quasicrystalline state after thermal treatment. It is also known that the amorphous and quasicrystal alloys belonging to the Ti[sub.45]Zr[sub.38]Ni[sub.17] family are able to store hydrogen and yield gravimetric densities above 2 wt.%. In this contribution, we report the results of research on the Ti[sub.45]Zr[sub.38]Ni[sub.17] system with vanadium doped instead of titanium. We found that the amorphous samples with moderate doping (x < 20) show the ability to absorb hydrogen while maintaining the amorphous state and they transform into the novel glassy-quasicrystal phase during annealing. Those materials with higher vanadium concentrations do not form entirely amorphous structures. However, they still can absorb hydrogen easily. It was also confirmed that the in situ hydrogenation of the amorphous alloys is a straightforward process without decomposition of the alloy. In this process, hydrogen does not attach to any particular constituent of the alloy, which would lead to the formation of simple hydrides or nanoclusters. Therefore, we were able to confirm the fully amorphous nature of the deuterides/hydrides of the Ti[sub.45−x]V[sub.x]Zr[sub.38]Ni[sub.17] with moderate V doping.