Electrochemical two-electron O2 reduction reaction toward H2O2 production: using cobalt porphyrin decorated carbon nanotubes as a nanohybrid catalyst. Issue 46 (17th November 2021)

• Record Type: Journal Article
• Authors: Dong, Kai; Liang, Jie; Ren, Yuchun; Wang, Yuanyuan; Xu, Zhaoquan; Yue, Luchao; Li, Tingshuai; Liu, Qian; Luo, Yonglan; Liu, Yang; Gao, Shuyan; Hamdy, Mohamed S.; Li, Quan; Ma, Dongwei; Sun, Xuping
• Is Part Of: Journal of materials chemistry. Volume 9:Issue 46(2021)
• Page Start: 26019
• Page End: 26027
• Publication Date: 2021-11-17
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1ta07989a
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : A Co-tetramethoxyphenylporphyrin/carbon nanotube hybrid efficiently electrocatalyzes H2 O2 production via 2e − O2 reduction with an ultrahigh mass activity. The catalytic mechanism is revealed by in situ infrared spectroscopy and DFT calculations. Abstract : Electroreduction of O2 into H2 O2 holds great promise to replace the energy-intensive anthraquinone process that is currently used as an industry standard, but its practical feasibility still requires materials with high catalytic efficiencies. It is now shown that a Co-tetramethoxyphenylporphyrin–carbon nanotube (CoTMPP/CNT) nanohybrid acts as a high-performance catalyst with fast electron delivery to active sites toward electrochemically generating H2 O2 under acidic aqueous conditions, achieving a H2 O2 selectivity of over 95% and achieving strong stability. More impressively, it reduces O2 to H2 O2 with an unprecedented mass activity of 9694 A g −1 and a high turnover frequency of up to 6.95 s −1 (0.6 VRHE ), representing the most active molecule-based two-electron O2 reduction reaction (ORR) electrocatalyst under an acidic environment so far. It also performs efficiently in neutral media. Taking advantage of the well-defined structure of the TMPP unit, we systematically study the trends in catalytic activity as well as selectivity toward the ORR at the M–N4 site (M = Mn, Fe, Co, Ni, Cu) with an identical chemical environment of TMPP. In situ attenuated total reflection infrared spectroscopy and density functional theory calculations were used to reveal further the catalytic mechanism.