Adsorbed Hydroxyl and Water on Ni(111): Heats of Formation by Calorimetry
Adsorbed Hydroxyl and Water on Ni(111): Heats of Formation by Calorimetry
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DOI：
10.1021/acscatal.7b04041
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发表时间：
2018-01
期刊：
影响因子：
12.9
通讯作者：
W. Zhao;S. Carey;Zhongtian Mao;C. Campbell
中科院分区：
文献类型：
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作者：
W. Zhao;S. Carey;Zhongtian Mao;C. Campbell
吸附羟基是镍催化剂上许多催化反应的常见中间体。本文用单晶吸附量热法测定了D_2O在O-预覆盖的Ni（111）表面上产生吸附羟基的解离吸附热，在0.23 ML覆盖范围内，平均值为67.3 kJ/mol。由此，吸附在Ni（111）上的羟基的生成焓和羟基与Ni（111）的键能分别估计为−278.3和314.1 kJ/mol。D_2O在清洁Ni（111）上的分子吸附在0.5ML时的积分热为53.6kJ/mol。与Pt（111）相比，吸附的羟基与Ni（111）67 kJ/mol的结合更强，吸附的D2 O与Ni（111）<$2 kJ/mol的结合更强。这些能量学有助于澄清Ni与Pt的不同催化性能，并作为基准来评估表面化学中使用的量子力学方法的能量准确性。
Adsorbed hydroxyl is a common intermediate in many catalytic reactions on Ni catalysts. The heat of the dissociative adsorption of D2O onto an O-precovered Ni(111) surface producing adsorbed hydroxyls is measured here by single crystal adsorption calorimetry, with an average value of 67.3 kJ/mol up to 0.23 ML coverage. From this, the enthalpy of formation for adsorbed hydroxyl on Ni(111) and the bond energy of hydroxyl to Ni(111) were estimated to be −278.3 and 314.1 kJ/mol, respectively. The molecular adsorption of D2O on clean Ni(111) gave an integral heat of 53.6 kJ/mol at 0.5 ML. In comparison to Pt(111), adsorbed hydroxyl binds to Ni(111) 67 kJ/mol more strongly and adsorbed D2O binds to Ni(111) ∼ 2 kJ/mol more strongly. These energetics help clarify the different catalytic properties of Ni versus Pt, and serve as benchmarks to evaluate the energy accuracy of quantum mechanical methods used in surface chemistry.