Abstract

Identifying the active catalytic centers on catalyst surface is significant for exploring the catalytic reaction mechanism and further guiding the synthesis of high-performance catalysts. However, it remains a challange in developing the site-specific technology for the identification of the active catalytic centers. Herein, in-situ infrared spectroscopy of adsorbed CO, photo-catalytic hydrogen evolution reaction (HER) test and theoretical simulation were used to distinguish and quantify the different surface sites and their H₂-production catalytic activity on TiO₂-supported Pt nanoparticles (PtNPs). Two different types of surface Pt sites, tip Pt (Pt_tip) and edge/terrace Pt_edge/terrace, on TiO₂-supported Pt nanoparticles (PtNPs) were identified. The photocatalytic H₂-production activity of TiO₂-supported PtNPs shows a linear functional relationship with the number of Pt_tip sites. However, the number of Pt_edge/terrace sites produced little effect on the activity of TiO₂-supported PtNPs. First-principle simulations confirmed that H₂-evolution at the Pt_tip sites owns a lower energy barrier than that at Pt_edge/terrace. This findings would be helpful for the fabrication of high-performance Pt catalysts.

中文翻译：

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通过CO的原位红外光谱鉴定TiO 2负载的Pt纳米颗粒上的活性光催化H 2产生位点

摘要

识别催化剂表面的活性催化中心对于探索催化反应机理和进一步指导高性能催化剂的合成具有重要意义。但是，开发用于识别活性催化中心的特定位置技术仍然是一个挑战。本文中，使用吸附式CO的原位红外光谱，光催化制氢反应（HER）测试和理论模拟来区分和量化不同的表面位点及其对TiO ₂负载的Pt纳米颗粒的H _2生成催化活性（ PtNPs）。TiO ₂上两种不同类型的表面Pt位置，尖端Pt（Pt _tip）和边缘/露台Pt_{边缘/露台}鉴定了支持Pt的纳米颗粒（PtNPs）。TiO ₂负载的PtNPs的光催化H _2产生活性与Pt_尖端位点的数量呈线性函数关系。然而，Pt_{边缘/平台}位点的数量对TiO ₂负载的PtNPs的活性影响很小。第一性原理模拟证实，Pt_尖端位置的H ₂演化比Pt_{边缘/露台的}H ₂演化具有更低的能垒。该发现将对高性能Pt催化剂的制造有所帮助。