https://scholars.lib.ntu.edu.tw/handle/123456789/626787
Title: | The synergistic effect Pt-1-W dual sites as a highly active and durable catalyst for electrochemical methanol oxidation | Authors: | Awoke, YA Tsai, MC Adam, DB Ayele, AA Yang, SC Huang, WH Chen, JL Pao, CW CHUNG-YUAN MOU Su, WN Hwang, BJ |
Keywords: | Single-atom catalyst; Methanol oxidation reaction; Dual active sites; Selectivity; SINGLE-ATOM CATALYSTS; METAL-SUPPORT INTERACTIONS; DOPED TIO2 PHOTOCATALYSTS; IR; PD; ELECTROCATALYSTS; HYDROGENATION; NANOPARTICLES; CONVERSION; STABILITY | Issue Date: | 2022 | Publisher: | PERGAMON-ELSEVIER SCIENCE LTD | Journal Volume: | 432 | Source: | ELECTROCHIMICA ACTA | Abstract: | Downsizing precious metal catalysts such as Pt to the atomic level is considered effective and efficient in the catalysis industry. However, Pt single-atom alone cannot catalyze the MOR (methanol oxidation reaction) due to the requirement of Pt ensemble sites to activate C-O bonds. Herein, we report for the first Pt single atom dispersed on dual doped TiO2 (Pt1/ Ti0.8W0.2NxOy) as an effective and durable catalyst towards MOR. It is found that synergy between Pt1-WO3-x dual-active-sites enables the adsorption and dehydrogenation of methanol. Density functional theory (DFT) calculations reveal that W-site adsorbs methanol molecule and the synergistic cooperation between Pt1-W dual active sites in Pt1/Ti0.8W0.2NxOy contributes to the high catalytic activity, stability, and selectivity. The Pt1/ Ti0.8W0.2NxOy catalyst displays high MOR performance with a mass activity of 560 mA mg−1Pt at 0.82 V vs. RHE in an alkaline medium. This activity is 9.3 and 1.3 times higher than the corresponding Pt nanoparticle (2 wt% Pt/ Ti0.8W0.2NxOy) and 20% Pt/C catalysts, respectively. The lower Tafel slope (93 mV dec−1) and higher diffusion coefficient (1.5×10−12 cm2/s) indicate MOR is faster on Pt1/Ti0.82W0.18NxOy than the other catalysts. Furthermore, Pt1/ Ti0.8W0.2NxOy oxidizes methanol to formate with 90% selectivity, whereas 2 wt% Pt/Ti0.82W0.18NxOy to formaldehyde with 69% selectivity. Moreover, after 10 h, Pt1/ Ti0.8W0.2NxOy mass activity decayed only by 7.2%. In contrast, 2 wt% Pt/ Ti0.8W0.2NxOy and 20% Pt/C exhibited 23% and 43% of activity losses respectively. |
URI: | https://scholars.lib.ntu.edu.tw/handle/123456789/626787 | ISSN: | 0013-4686 | DOI: | 10.1016/j.electacta.2022.141161 |
Appears in Collections: | 化學系 |
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