Bagger Alexander, Ju Wen, Varela Ana Sofia, Strasser Peter, Rossmeisl Jan
Department of Chemistry, University of Copenhagen, Universitetsparken 5, Copenhagen, Denmark.
Department of Chemistry, Chemical Engineering Division, Technical University Berlin, 10623, Berlin, Germany.
Chemphyschem. 2017 Nov 17;18(22):3266-3273. doi: 10.1002/cphc.201700736. Epub 2017 Oct 19.
In this work, we propose four non-coupled binding energies of intermediates as descriptors, or "genes", for predicting the product distribution in CO electroreduction. Simple reactions can be understood by the Sabatier principle (catalytic activity vs. one descriptor), while more complex reactions tend to give multiple very different products and consequently the product selectivity is a more complex property to understand. We approach this, as a logistical classification problem, by grouping metals according to their major experimental product from CO electroreduction: H , CO, formic acid and beyond CO* (hydrocarbons or alcohols). We compare the groups in terms of multiple binding energies of intermediates calculated by density functional theory. Here, we find three descriptors to explain the grouping: the adsorption energies of H*, COOH*, and CO*. To further classify products beyond CO*, we carry out formaldehyde experiments on Cu, Ag, and Au and combine these results with the literature to group and differentiate alcohol or hydrocarbon products. We find that the oxygen binding (adsorption energy of CH O*) is an additional descriptor to explain the alcohol formation in reduction processes. Finally, the adsorption energy of the four intermediates, H*, COOH*, CO*, and CH O*, can be used to differentiate, group, and explain products in electrochemical reduction processes involving CO , CO, and carbon-oxygen compounds.
在这项工作中，我们提出了四种中间体的非耦合结合能作为描述符或“基因”，用于预测CO电还原中的产物分布。简单反应可通过萨巴蒂尔原理（催化活性与一个描述符的关系）来理解，而更复杂的反应往往会产生多种截然不同的产物，因此产物选择性是一个更复杂的性质，难以理解。我们将其作为一个逻辑分类问题来处理，根据CO电还原的主要实验产物对金属进行分组：H₂、CO、甲酸以及CO之外的产物（碳氢化合物或醇类）。我们根据密度泛函理论计算的中间体的多种结合能来比较这些组。在这里，我们发现了三个描述符来解释这种分组：H、COOH和CO的吸附能。为了进一步对CO之外的产物进行分类，我们对Cu、Ag和Au进行了甲醛实验，并将这些结果与文献相结合，对醇类或碳氢化合物产物进行分组和区分。我们发现氧结合（CH₂O的吸附能）是解释还原过程中醇类形成的另一个描述符。最后，H*、COOH*、CO和CH₂O这四种中间体的吸附能可用于区分、分组和解释涉及CO₂、CO和碳氧化合物的电化学还原过程中的产物。
