...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>The journal of physical chemistry, C. Nanomaterials and interfaces >Observation of Surface-Bound Negatively Charged Hydride and Hydroxide on GaP(110) in H2O Environments
【24h】

Observation of Surface-Bound Negatively Charged Hydride and Hydroxide on GaP(110) in H2O Environments

机译：H2O环境中GaP（110）表面结合负电荷的氢化物和氢氧根的观察

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Surface-bound species on GaP(110) formed upon interaction with water were investigated through experiment and theory. These studies are motivated by and discussed in the context of electrocatalytic and photoelectrocatalytic schemes for solar fuel production, including especially observations of selective CO2 reduction to methanol in acidified aqueous solutions of CO2 and nitrogen-containing heteroaromatics. Experimentally, surface-bound species over 10 orders of magnitude of pressure were spectroscopically identified in situ using synchrotron-based ambient pressure photoelectron spectroscopy. Ga 3d and O 1s core-level spectra indicate that the interaction of GaP(110) with H2O induces formation of a partially dissociated adlayer, characterized by the presence of both Ga-OH and molecular H2O species. Measurements of the P 2p core level indicate formation of a negatively charged hydride that irreversibly bonds to surface P in vacuum. The surface densities of the hydroxide and hydride species increase with increasing pressure (surface coverage) of water. Periodic slab calculations using density functional theory were used to study several relevant water configurations at 298 K on this surface. Consistent with earlier theoretical predictions at 0 K, the calculations confirm that Ga-OH, molecular H2O, and P-H species are thermodynamically stable on the GaP(110) surface under experimental conditions. Isobaric measurements at elevated pressures were used to probe the thermal stabilities of adsorbed species as well as the oxidation of surface Ga and P. The observation of stable surface hydride formation induced by interaction with water is especially notable given the critical role of hydride transfer to catalysts and CO2 during chemical fuel synthesis reactions in aqueous environments. It is hypothesized that the observed high stability of the hydride on GaP may contribute to its associated remarkable near-100% faradaic efficiency for methanol generation by solar-driven CO2 reduction in acidified aqueous pyridine solutions [J. Am. Chem. Soc.2008, 130, 6342] because such stability is known to yield high overpotentials for the competing hydrogen evolution reaction.
机译：通过实验和理论研究了GaP（110）与水相互作用时形成的表面结合物种。这些研究是受用于太阳能燃料生产的电催化和光电催化方案的启发和讨论的，特别是观察到在酸化的CO2和含氮杂芳族水溶液中将CO2选择性还原为甲醇的观察。实验上，使用基于同步加速器的环境压力光电子能谱仪在光谱上原位识别了超过10个数量级压力的表面结合物质。 Ga 3d和O 1s的核心能谱表明GaP（110）与H2O的相互作用诱导了部分离解的adlayer的形成，其特征是同时存在Ga-OH和分子H2O。对P 2p核心能级的测量表明，在真空中形成了不可逆地与表面P结合的带负电荷的氢化物。氢氧化物和氢化物的表面密度随着水的压力（表面覆盖率）的增加而增加。使用密度泛函理论对板坯进行定期计算，以研究该表面在298 K下的几种相关水构型。与早期在0 K上的理论预测一致，这些计算证实了在实验条件下Ga-OH，分子H2O和P-H物种在GaP（110）表面上是热力学稳定的。高压下的等压测量用于探测被吸附物质的热稳定性以及表面Ga和P的氧化。与水相互作用引起的稳定表面氢化物形成的观察尤其值得注意，因为氢化物转移到催化剂中起关键作用在水性环境中进行化学燃料合成反应时产生的二氧化碳和二氧化碳。假设观察到的氢化物在GaP上的高稳定性可能有助于其在酸性吡啶水溶液中通过太阳驱动的CO2还原而产生显着的接近100％的法拉第效率[J]。上午。化学[Soc.2008，130，6342]，因为已知这种稳定性会为竞争的氢释放反应产生高的超电势。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号