Wen-Jun Yi

High-efficiency catalytic performance over mesoporous Ni/beta zeolite for the synthesis of quinoline from glycerol and aniline

A green route for the vapor-phase synthesis of quinoline from glycerol and aniline was developed in this work, employing Ni/mesoporous beta zeolite (denoted as Ni/Hβ-At) as a catalyst. The mesoporous beta zeolite was prepared by alkaline treatment. Various influencing factors were systematically investigated. Both mesopores and the type of acid sites of the catalyst played important functions in catalytic activity for the synthesis of quinoline. Mesopores facilitated the transport of bulky products from internal surface of the catalyst. Meanwhile, weak Bronsted acid sites favored the dehydration of glycerol to acrolein and the existence of Lewis acid sites could accelerate the formation of quinoline. The Ni/Hβ-At catalyst exhibited the highest catalytic activity; and as high as a 71.4% yield of quinoline was obtained under the optimized reaction conditions. An enhanced ability of anti-deactivation was also displayed, due to the existence of mesopores on the Ni/Hβ-At catalyst facilitating the transport of bulky products and restraining the deposition of the coke. Meanwhile, it was found that the coke was main reason leading to catalyst deactivation and its performance was basically regenerated. The catalytic properties were slightly lower after 3 reaction–regeneration cycles. Finally, a feasible reaction pathway was proposed on the basis of the various products.

Hydrogenation of 3-hydroxypropanal to 1,3-propanediol over a Cu–V/Ni/SiO2 catalyst

A Ni-based catalyst modified with copper and vanadium (5Cu–20V/30Ni/SiO2) was synthesized and employed in the hydrogenation of 3-hydroxypropanal (3-HPA) to 1,3-propanediol (1,3-PDO). Catalysts were systematically characterized via XRD, TEM, HRTEM, SAED, H2-TPD, N2 physisorption, H2-TPR, and XPS. It was indicated that the addition of Cu and V not only promoted the reduction of Ni2+ species and the generation of active hydrogen species, but also increased the dispersion of Ni species and the interaction between Ni particles and SiO2. The catalytic performance evaluation showed that the (5Cu–20V/30Ni/SiO2) could provide the largest yield of 1,3-PDO (above 76.8%) and highest TOF (4.32 × 103 s−1). The structure–activity relationship was clarified according to the characterization results. The optimized reaction conditions over the 5Cu–20V/30Ni/SiO2 catalyst were obtained as the reaction temperature of 80 °C, a H2 pressure of 2.0 MPa (H2), and an LHSV of 0.4 h−1. The employment of non-noble metals, the relatively low pressure of H2, and the relatively high yield of 1,3-PDO make 5Cu–20V/30Ni/SiO2 an efficient and economic catalyst that may have potential applications in industry.

Synthesis of poly(L-lactide)/β-cyclodextrin/citrate network modified hydroxyapatite and its biomedical properties

Hydroxyapatite (HA) was modified by the chelation of citric acid and Ca2+ on the surface of HA, followed by cross-linking between the hydroxyl groups of β-cyclodextrin (β-CD) and citrate, and then further in situ ring-opening polymerization of L-lactide over the hydroxyl groups. The modification of HA adjusted its surface properties and reduced the particle size. The synthesized PLA-CD-HA-72 exhibited the good adhesion of mesenchymal stem cells (MSCs) of Wistar rats, higher viability of MSCs and larger osteoinductivity. The results indicated that the PLA-CD-HA-72 possessed a rather large biocompatibility and bioactivity, and it could be a promising candidate as a bone tissue engineering material.

Hydrogenation of 3-hydroxypropanal into 1,3-propanediol over bimetallic Ru–Ni catalyst

A series of Ni-based catalysts, including Ru/SiO2, Ni/SiO2 and Ru–Ni/SiO2, were prepared and employed in the hydrogenation of 3-hydroxypropanal (3-HPA) to 1,3-propanediol (1,3-PDO). The catalysts were systematically characterized by means of XRD, TEM, HRTEM, SEAD, XPS, H2-TPD, H2-TPR and N2-physisorption. It was indicated that the introduction of Ru onto the Ni/SiO2 not only increased the porosity of catalyst and the degree of dispersion of Ni species but also promoted the reduction of Ni2+ to Ni0 and the generation of active hydrogen species. The catalytic performance evaluation showed that the Ru–40Ni/SiO2 catalyst, among all others, could provide the largest yield of 1,3-PDO (above 99.0%) and highest TOF (4.70 × 103 S−1). The optimized reaction conditions over the Ru–40Ni/SiO2 catalyst had been established as follows: reaction temperature = 80 °C, H2 pressure = 2.0 MPa and LHSV = 0.4 h−1. In consideration of its extremely low H2 pressure and very high yield of 1,3-PDO for the hydrogenation of 3-HPA, to the best of our knowledge, the Ru–40Ni/SiO2 catalyst appeared to be the most efficient catalyst among all others reported in the literature. The good performance enabled the Ru–40Ni/SiO2 catalyst to be very promising in its industrial application.