China University of Petroleum

About: China University of Petroleum is a education organization based out in Beijing, China. It is known for research contribution in the topics: Catalysis & Oil shale. The organization has 39802 authors who have published 39151 publications receiving 483760 citations. The organization is also known as: Zhōngguó Shíyóu Dàxué & China University of Petroleum (Beijing).

Cobalt phosphide-based electrocatalysts: synthesis and phase catalytic activity comparison for hydrogen evolution

Abstract: Cobalt phosphides have been used as promising electrocatalysts for catalyzing the hydrogen evolution reaction (HER) in acidic aqueous solutions. In order to further explore the influence of phase structure and support effect on the catalytic activity for HER, herein, a series of cobalt phosphide-based electrocatalysts, including Co2P, CoP, Co2P/CNTs, CoP/CNTs, Co2P/NCNTs and CoP/NCNTs, were synthesized successfully via a facile thermal decomposition approach. The crystalline phase can be controlled by changing the phosphide source species. When the phosphide source was trioctylphosphine, CoP-based catalysts were obtained. However, Co2P-based catalysts can be obtained by using triphenylphosphine as the phosphide source. Then the phase catalytic activity and stability of the as-synthesized cobalt phosphide-based catalysts for hydrogen evolution were compared. The results show that the catalytic activity followed the order CoP/NCNTs > Co2P/NCNTs > CoP/CNTs > Co2P/CNTs > CoP > Co2P, which can be attributed to the different atomic ratios of Co to P, the strong interaction between cobalt phosphide and carbon species and the doping of N atoms into CNTs. Our studies indicate that the HER catalytic efficiency of transition metal phosphide catalysts can be improved significantly by adjusting active phase and carbon species structures.

Nanographene-constructed carbon nanofibers grown on graphene sheets by chemical vapor deposition: high-performance anode materials for lithium ion batteries.

Abstract: We report on the fabrication of 3D carbonaceous material composed of 1D carbon nanofibers (CNF) grown on 2D graphene sheets (GNS) via a CVD approach in a fluidized bed reactor. Nanographene-constructed carbon nanofibers contain many cavities, open tips, and graphene platelets with edges exposed, providing more extra space for Li(+) storage. More interestingly, nanochannels consisting of graphene platelets arrange almost perpendicularly to the fiber axis, which is favorable for lithium ion diffusion from different orientations. In addition, 3D interconnected architectures facilitate the collection and transport of electrons during the cycling process. As a result, the CNF/GNS hybrid material shows high reversible capacity (667 mAh/g), high-rate performance, and cycling stability, which is superior to those of pure graphene, natural graphite, and carbon nanotubes. The simple CVD approach offers a new pathway for large-scale production of novel hybrid carbon materials for energy storage.

Activation of peroxymonosulfate by carbonaceous oxygen groups: experimental and density functional theory calculations

Abstract: The active sites for metal-free carbocatalysis in environmental remediation are intricate compared to those for traditional metal-based catalysis. In this study, we report a facile fabrication of amorphous carbon spheres with varying oxygen functional groups by hydrothermal treatment of glucose solutions. With air/N2 annealing and regeneration in the glucose solution of the as-synthesized carbon spheres, the concentrations of oxygen-containing groups were tailored on the amorphous carbon spheres in an Excess-On-Off-On manner. Accordingly, an Off-On-Off-On catalytic behavior in peroxymonosulfate (PMS) activation using these amorphous carbon spheres was observed. To uncover the mechanism of catalytic activity, electron spin resonance (EPR) spectra were recorded to investigate the variation of the generated OH and SO4 −radicals. Moreover, density functional theory (DFT) studies were employed to identify the role of oxygen-containing groups on the amorphous carbon spheres in adsorptive O O bond activation of PMS. Results revealed that ketone groups (C O) are the dominant active sites for PMS activation among oxygen-containing functional groups. In order to simulate real wastewater treatment, influences of chloride anions and humic acid on PMS activation for phenol degradation were further evaluated. This study provides an in-depth insight to discovering the role of oxygen-containing functional groups as the active sites in metal-free carbocatalysis.