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Elucidation of Pathways for NO Electroreduction on Pt(111) from First Principles
Author(s) -
Clayborne Andre,
Chun HeeJoon,
Rankin Rees B.,
Greeley Jeff
Publication year - 2015
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201502104
Subject(s) - chemistry , dissociation (chemistry) , electrokinetic phenomena , ammonia , electrochemistry , protonation , aqueous solution , kinetics , oxide , photochemistry , reaction mechanism , nitrite , inorganic chemistry , computational chemistry , catalysis , electrode , organic chemistry , ion , physics , quantum mechanics , nitrate
The mechanism of nitric oxide electroreduction on Pt(111) is investigated using a combination of first principles calculations and electrokinetic rate theories. Barriers for chemical cleavage of NO bonds on Pt(111) are found to be inaccessibly high at room temperature, implying that explicit electrochemical steps, along with the aqueous environment, play important roles in the experimentally observed formation of ammonia. Use of explicit water models, and associated determination of potential‐dependent barriers based on Bulter–Volmer kinetics, demonstrate that ammonia is produced through a series of water‐assisted protonation and bond dissociation steps at modest voltages (<0.3 V). In addition, the analysis sheds light on the poorly understood formation mechanism of nitrous oxide (N 2 O) at higher potentials, which suggests that N 2 O is not produced through a Langmuir–Hinshelwood mechanism; rather, its formation is facilitated through an Eley–Rideal‐type process.