Atomically Dispersed Pt–N3C1 Sites Enabling Efficient and Selective Electrocatalytic C–C Bond Cleavage in Lignin Models under Ambient Conditions

Autor: Yadong Li, Chenliang Ye, Lina Ma, Ge Meng, Jiangwei Zhang, Dingsheng Wang, Xiao Liang, Han-Shi Hu, Tingting Cui, Zedong Zhang, Shibin Wang, Lirong Zheng, Haohong Duan
Rok vydání: 2021
Předmět:
Zdroj: Journal of the American Chemical Society. 143:9429-9439
ISSN: 1520-5126
0002-7863
Popis: Selective cleavage of C-C linkages is the key and a challenge for lignin degradation to harvest value-added aromatic compounds. To this end, electrocatalytic oxidation presents a promising technique by virtue of mild reaction conditions and strong sustainability. However, the existing electrocatalysts (traditional bulk metal and metal oxides) for C-C bond oxidative cleavage suffer from poor selectivity and low product yields. We show for the first time that atomically dispersed Pt-N3C1 sites planted on nitrogen-doped carbon nanotubes (Pt1/N-CNTs), constructed via a stepwise polymerization-carbonization-electrostatic adsorption strategy, are highly active and selective toward Cα-Cβ bond cleavage in β-O-4 model compounds under ambient conditions. Pt1/N-CNTs exhibits 99% substrate conversion with 81% yield of benzaldehyde, which is exceptional and unprecedented compared with previously reported electrocatalysts. Moreover, Pt1/N-CNTs using only 0.41 wt % Pt achieved a much higher benzaldehyde yield than those of the state-of-the-art bulk Pt electrode (100 wt % Pt) and commercial Pt/C catalyst (20 wt % Pt). Systematic experimental investigation together with density functional theory (DFT) calculation suggests that the superior performance of Pt1/N-CNTs arises from the atomically dispersed Pt-N3C1 sites facilitating the formation of a key Cβ radical intermediate, further inducing a radical/radical cross-coupling path to break the Cα-Cβ bond. This work opens up opportunities in lignin valorization via a green and sustainable electrochemical route with ultralow noble metal usage.
Databáze: OpenAIRE