钯纳米粒子上活性氢物种的鉴定，用于水中2,4-二氯苯酚的增强电催化加氢脱氯,Environmental Science & Technology

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钯纳米粒子上活性氢物种的鉴定，用于水中2,4-二氯苯酚的增强电催化加氢脱氯
Environmental Science & Technology ( IF 10.8 ) Pub Date : 2017-05-25 00:00:00 , DOI: 10.1021/acs.est.7b01128
Guangming Jiang ₁ , Mengna Lan ₁ , Zhiyong Zhang ₂ , Xiaoshu Lv ₁ , Zimo Lou ₃ , Xinhua Xu ₃ , Fan Dong ₁ , Sen Zhang ₂

Affiliation

澄清氢的逸出和识别活性氢的种类对于理解电催化加氢脱氯（EHDC）机理至关重要。在此，单分散钯纳米颗粒（Pd NPs）被用作模型催化剂，以证明三种氢物种的势态依赖演化，包括吸附的原子氢（H * ads），吸附的原子氢（H * abs）和分子氢（H2））对Pd NPs的影响，然后它们对2,4-二氯苯酚（2,4-DCP）的EHDC产生影响。我们的结果表明，H * ads，H * abs和H2均出现在-0.65 V（vs. Ag / AgCl）处，并且在更多的负电势下具有增加的量，除了H * ads呈现相反的趋势，其电势从-0.85至-0.95V。总体而言，这三种物质的浓度在-0.65〜-0的电位范围内以H * abs <H * ads <H2的顺序变化。85 V，-0.85〜-1.00 V中的H * ads <H * abs <H2，-1.00〜-1.10 V中的H * ads <H2 <H * abs DCP EHDC动力学和效率，我们发现H * ads是活性物质，H * abs是惰性的，而H2气泡对EHDC反应有害。因此，为了有效的EHDC反应，期望中等的电位以产生足够的H * ads并限制H 2负面作用。我们的工作对EHDC在Pd催化剂上的反应机理进行了系统的研究，应促进EHDC技术在实际环境修复中的应用。H * abs是惰性的，而H2气泡对EHDC反应有害。因此，为了有效的EHDC反应，期望中等的电位以产生足够的H * ads并限制H 2负面作用。我们的工作对EHDC在Pd催化剂上的反应机理进行了系统的研究，应促进EHDC技术在实际环境修复中的应用。H * abs是惰性的，而H2气泡对EHDC反应有害。因此，为了有效的EHDC反应，期望中等的电位以产生足够的H * ads并限制H 2负面作用。我们的工作对EHDC在Pd催化剂上的反应机理进行了系统的研究，应促进EHDC技术在实际环境修复中的应用。

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Identification of Active Hydrogen Species on Palladium Nanoparticles for an Enhanced Electrocatalytic Hydrodechlorination of 2,4-Dichlorophenol in Water

Clarifying hydrogen evolution and identifying the active hydrogen species are crucial to the understanding of electrocatalytic hydrodechlorination (EHDC) mechanism. Here, monodisperse palladium nanoparticles (Pd NPs) are used as a model catalyst to demonstrate the potential-dependent evolutions of three hydrogen species, including adsorbed atomic hydrogen (H*ads), absorbed atomic hydrogen (H*abs) and molecular hydrogen (H2) on Pd NPs, and then their effect on EHDC of 2,4-dichlorophenol (2,4-DCP). Our results show that H*ads, H*abs and H2 all emerge at -0.65 V (vs. Ag/AgCl), and have increased amounts at more negative potentials, except for H*ads that exhibits a reversed trend with potential varying from -0.85 to -0.95 V. Overall, the concentrations of these three species evolve in an order of H*abs<H*ads<H2 in potential range of -0.65~-0.85 V, H*ads<H*abs<H2 in -0.85~-1.00 V and H*ads<H2<H*abs in -1.00~-1.10 V. By correlating the evolution of each hydrogen species with 2,4-DCP EHDC kinetics and efficiency, we find that H*ads is the active species, H*abs is inert while H2 bubbles are detrimental to EHDC reaction. Accordingly, for an efficient EHDC reaction, a moderate potential is desired to yield sufficient H*ads and limit H2 negative effect. Our work presents a systematic investigation on the reaction mechanism of EHDC on Pd catalysts, which should advance the application of EHDC technology in practical environmental remediation.

更新日期：2017-05-27

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