Theoretical Study of the Decomposition and Hydrogenation of H2O2 on Pd and Au@Pd Surfaces: Understanding toward High Selectivity of H2O2 Synthesis
Theoretical Study of the Decomposition and Hydrogenation of H2O2 on Pd and Au@Pd Surfaces: Understanding toward High Selectivity of H2O2 Synthesis
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DOI：
10.1021/jp1070456
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发表时间：
2011-03
影响因子：
3.7
通讯作者：
Jun Li;A. Staykov;T. Ishihara;K. Yoshizawa
中科院分区：
文献类型：
--
作者：
Jun Li;A. Staykov;T. Ishihara;K. Yoshizawa
用周期密度泛函理论计算研究了Pd和Au@Pd催化剂上H2 O2转化为水的三种可能途径：（1）H2 O2的分解（H2 O2 → H2O + O），包括H2 O2解离成两个OH基团（H2 O2 → 2 OH）和两个OH基团的反硝化作用，以水和氧（OH + OH → H2O + O）;（2）OH基团氢化成水（OH + H → H2O）;和（3）H2 O2直接氢化成水（H2 O2 + 2 H → 2 H2O）。结果表明，H2 O2的分解和OH基团的氢化是水生成的两个有效途径，其中H2 O2的分解起主要作用。整个过程中的一个关键步骤是H2 O2的解离，这是容易的和不可逆的。H2 O2直接氢化成水具有非常高的活化势垒，并且不太可能发生。分析了Pd和Au@Pd表面上H2 O2解离和释放之间的竞争。H2 O2合成反应的高选择性。
Three possible pathways for the conversion of hydrogen peroxide to water on Pd and Au@Pd catalysts are investigated with periodic density functional theory calculations: (1) the decomposition of H2O2 (H2O2 → H2O + O), including the dissociation of H2O2 to two OH groups (H2O2 → 2OH) and the disproportionation of two OH groups to water and oxygen (OH + OH → H2O + O); (2) the hydrogenation of the OH group to water (OH + H → H2O); and (3) the direct hydrogenation of H2O2 to water (H2O2 + 2H → 2H2O). The results show that the decomposition of H2O2 and the hydrogenation of OH groups are two available channels for the formation of water, and the former plays a main role. A key step in the overall process is the dissociation of H2O2, which is facile and irreversible. The direct hydrogenation of H2O2 to water has a very high activation barrier and is unlikely to occur. The competitions between the dissociation of H2O2 and the release of H2O2 on Pd and Au@Pd surfaces are analyzed. The high selectivity of H2O2 synth...