Search

Your search keyword '"Liang, Changhai"' showing total 890 results
Start Over Author "Liang, Changhai"
890 results on '"Liang, Changhai"'

35. Long‐Durability, Surfactant‐Free, and Bifunctional Ir‐Doped Pt3Co/MWCNTs Electrocatalysts towards ORR and OER in Acidic Media.

Author

Wang, Qiang, Li, Chuang, Li, Guangwei, Li, Xiao, Luo, Sai, Xing, Danmin, and Liang, Changhai

Subjects
OXYGEN evolution reactions, MULTIWALLED carbon nanotubes, PHOTOELECTRON spectroscopy, HYDROGEN as fuel, OXYGEN reduction, HYDROGEN evolution reactions, ELECTROCATALYSTS
Abstract

Developing cost‐effective, high‐performance, and durable electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is pivotal for advancing hydrogen energy conversion and storage technologies. Simultaneously, establishing scalable methods for their production is essential for the widespread adoption of these renewable energy solutions. In this study, we present a successful large‐scale synthesis of surfactant‐free iridium‐doped Pt−cobalt nanoparticles supported on multiwalled carbon nanotubes (Ir−Pt3Co/MWCNTs). This composite demonstrates significantly enhanced ORR and OER activity compared to commercial Pt/C and IrO2 in acidic environments. The Ir−Pt3Co/MWCNTs catalyst composite exhibits a low overpotential of 357 mV at 10 mA cm−2 and a remarkable mass activity of 0.594 A/mgPt. Investigating the influence of Ir doping content on ORR and OER, we found that Pt3Co0.6Ir0.4/MWCNTs showcased the most superior activity in both reactions. We present a reproducible protocol for the synthesis of surfactant‐free Ir−Pt3Co nanoparticles supported on MWCNTs, yielding a bifunctional catalyst capable of efficiently catalyzing both ORR and OER with outstanding efficiency and stability in acidic media. Detailed X‐ray photoelectron spectroscopy (XPS) analysis elucidates the electron transfer between atoms, optimizing the electronic structure and adjusting the position of the d‐band. This optimization enhances the electrocatalytic activity and structural stability of the catalysts, contributing to their superior performance in ORR and OER. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

47. Catalytic Oxidation of Benzyl Alcohol by Gold Nanoparticles on Carbon Residue–Modified CoAlOxSpinel

Author

Zhang, Sen, Du, Zhongtian, Bao, Meihui, Gao, Nan, Luo, Jingjie, and Liang, Changhai

Abstract

Stable and efficient gold catalysts can be alternative candidates to catalyze the primary alcohol oxidation for the sustainable chemical industry. We have synthesized a series of Au catalysts supported by spinel CoxAl-C modified with carbon skeleton for the alkali-free aerobic oxidation of benzyl alcohol. The influences of the Co/Al molar ratio and the residual carbon on the surface structure of gold catalysts were studied and correlated with their catalytic behavior. Characterizations including XRD, XPS and UPS, SEM and TEM, and N2adsorption–desorption were operated to understand the chemical composition and surface metal states in different catalysts. The results suggested that under an appropriate Co/Al ratio, Au/Co1Al-C has a higher amount of Auδ+induced by the promoted electronic environment. The presence of Co2+/Co3+contributed to the formation of oxygen vacancies. The residual carbon skeleton increased the surface area and decreased the overall work function of the catalyst with an accelerated charge transfer between Au and the adsorbate. The faster alkali-free conversion rate of benzyl alcohol was achieved by Au/Co1Al-C and Au/Co2Al-C even under quite low temperatures. Approximately 82% benzaldehyde yield was obtained by Au/Co1Al-C with a TOF value of 2056 h–1at 80 °C.

Published
2024
Full Text
View/download PDF

48. Amine-functionalized metal-organic frameworks loaded with Ag nanoparticles for cycloaddition of CO2 to epoxides.

Author

Fu, Huiyu, Wu, Jiewen, Liang, Changhai, and Chen, Xiao

Abstract

With the advantages of low raw material cost and 100% atom utilization, the synthesis of high value-added chemical product cyclic carbonates by the cycloaddition of CO2 to epoxides has become one of the most prospective approaches to achieve the industrial utilization of CO2. In the reported catalytic systems, the complexity of the catalyst synthesis process, high cost, separation difficulties, and low CO2 capture limit the catalytic efficiency and its large-scale application. In this paper, Ag nanoparticles loaded on polyethyleneimine (PEI)-modified UiO-66-NH2 (Ag/PEI@UiO-66-NH2) are successfully synthesized by in situ immersion reduction. The Ag nanoparticles and the amino groups on the surfaces of PEI@UiO-66-NH2 contribute to the adsorption of CO2 and polarization of C–O bonds in epoxides, thereby boosting the conversion capability for the CO2 cycloaddition reaction. At the amount of propylene oxide of 0.25 mol and the catalyst dosage of 1% of the substrate, the yield and selectivity of propylene carbonate are up to 99%. In addition, the stability and recyclability of Ag/PEI@UiO-66-NH2 catalyst are attained. The Ag/PEI@UiO-66-NH2 catalyst also demonstrates a wide range of activity and distinctive selectivity toward cyclo-carbonates in the cycloaddition of CO2 to epoxides. This work provides a guide to designing a highly efficient catalyst for in situ capture and high-value utilization of CO2 in industrial applications. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results