宋丽川, 钟栎锭, 沈佳, 娄亚珂, 郭耘, 王丽. γ-Al2O3形貌调控对PtCo合金化程度在CO-PROX反应中的影响[J]. 燃料化学学报(中英文). DOI: 10.1016/S1872-5813(24)60466-4
引用本文: 宋丽川, 钟栎锭, 沈佳, 娄亚珂, 郭耘, 王丽. γ-Al2O3形貌调控对PtCo合金化程度在CO-PROX反应中的影响[J]. 燃料化学学报(中英文). DOI: 10.1016/S1872-5813(24)60466-4
SONG Lichuan, ZHONG Liding, SHEN Jia, LOU Yake, GUO Yun, WANG Li. Tuning support morphology to control alloy over PtCo/γ-Al2O3 for the preferential oxidation of CO[J]. Journal of Fuel Chemistry and Technology. DOI: 10.1016/S1872-5813(24)60466-4
Citation: SONG Lichuan, ZHONG Liding, SHEN Jia, LOU Yake, GUO Yun, WANG Li. Tuning support morphology to control alloy over PtCo/γ-Al2O3 for the preferential oxidation of CO[J]. Journal of Fuel Chemistry and Technology. DOI: 10.1016/S1872-5813(24)60466-4

γ-Al2O3形貌调控对PtCo合金化程度在CO-PROX反应中的影响

Tuning support morphology to control alloy over PtCo/γ-Al2O3 for the preferential oxidation of CO

  • 摘要: 本工作通过水热法制备了不同形貌的γ-Al2O3:暴露(110)晶面的花球状γ-Al2O3(f)、暴露(100)晶面的片状γ-Al2O3(s)、以及暴露(111)晶面的棒状γ-Al2O3(r),随后负载PtCo纳米颗粒。载体的形貌及暴露晶面影响了PtCo纳米颗粒的合金化程度,随着合金化程度的增加,催化剂的活性也随之增强。PtCo/γ-Al2O3 (f)上形成了具有特定结构的Pt3Co金属间化合物,其在CO-PROX反应中表现出较高的催化活性,可在50−225 ℃实现CO完全转化,且具有优异的抗H2O和CO2性能;在γ-Al2O3(s)上仅发现PtCo部分合金化;而PtCo/γ-Al2O3(r)中Pt、Co之间没有出现合金化现象,其在50 ℃下的反应速率仅为PtCo/γ-Al2O3(f)的11%。机理研究表明,形成Pt3Co金属间化合物使Pt更偏氧化态,显著削弱了Pt上CO的吸附并增加了活性氧物种,促进了CO的选择氧化。

     

    Abstract: The preferential oxidation of CO (CO-PROX) reaction is a cost-effective method for eliminating trace amounts of CO from the fuel H2. Pt-based catalysts have been extensively studied for CO-PROX, with their activity influenced by the morphology of the support. Hydrothermal synthesis was employed to produce different morphologies of γ-Al2O3: flower-like γ-Al2O3 (f) exposing (110) crystal faces, sheet-like γ-Al2O3 (s) revealing (100) crystal faces, and rod-like γ-Al2O3 (r) displaying (111) crystal faces, followed by loading PtCo nanoparticles. The exposed crystal faces of the support impact the alloying degree of the PtCo nanoparticles, and an increase in the alloying degree correlates with enhanced catalyst reactivity. Pt3Co intermetallic compounds were identified on γ-Al2O3 (f) exposing (110) crystal faces, and PtCo/γ-Al2O3 (f) showed high catalytic activity in the CO-PROX reaction, achieving 100% CO conversion across a broad temperature range of 50−225 °C. In contrast, only partial alloying of PtCo was observed on γ-Al2O3(s). Furthermore, no alloying between Pt and Co occurred in PtCo/γ-Al2O3 (r), resulting in a reaction rate at 50 °C that was merely 11% of that of PtCo/γ-Al2O3 (f). The formation of Pt3Co intermetallic compounds led to a more oxidized state of Pt, which significantly diminished the adsorption of CO on Pt and augmented the active oxygen species, thereby facilitating the selective oxidation of CO.

     

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