TY - JOUR
T1 - Understanding and tuning the hydrogen evolution reaction on Pt-covered tungsten carbide cathodes
AU - Zhuang, Houlong
AU - Tkalych, Alexander J.
AU - Carter, Emily A.
N1 - Funding Information:
We are grateful to the Air Force Office of Scientific Research for funding (grant No. FA9550-14-1-0254). We acknowledge use of the TIGRESS high performance computer center at Princeton University. We also acknowledge use of the COPPER supercomputer at the Air Force Office of Scientific Research High Performance Computing Center. We thank Nari Baughman, Dr. Johannes Dieterich, and Dr. Mark Martirez for critical reading of this manuscript. We thank Martina Lessio and Andrew Ritzmann for the help with the vibrational frequency calculations.
Publisher Copyright:
© 2016 The Electrochemical Society.
PY - 2016
Y1 - 2016
N2 - Understanding and tailoring the interactions between hydrogen (H) atoms and catalytic surfaces is critical to developing electro-catalysts with less platinum (Pt). Tungsten carbide (WC) is a possible valence isoelectronic substitute for Pt. Using first-principles quantum mechanics calculations, we systematically investigate H binding to WC(0001) and Pt(111) surfaces. Moreover, inspired by recent experiments on hybrid monolayer-Pt/WC catalysts, we study H adsorption on these hybrid surfaces. We consider both W and C terminations and vary the number of Pt layers. We predict that the H binding energy (HBE) plateaus rapidly with the number of Pt layers and that a monolayer of Pt on a WC substrate has a similar HBE to that of pure Pt. This corroborates the experimental observation that the two systems exhibit similar electrochemical activities. Increasing the number of Pt layers leads to a slight increase in the HBE and a projected decrease in catalytic activity. Through various electronic structure analyses, we show that the similarity in activities is due to an intrinsic alteration of the character of the Pt/WC surface rather than a similarity to the pure Pt surface. Our findings provide guidance for tuning parameters that affect catalytic activity by controlling WC surface termination and Pt overlayer thickness.
AB - Understanding and tailoring the interactions between hydrogen (H) atoms and catalytic surfaces is critical to developing electro-catalysts with less platinum (Pt). Tungsten carbide (WC) is a possible valence isoelectronic substitute for Pt. Using first-principles quantum mechanics calculations, we systematically investigate H binding to WC(0001) and Pt(111) surfaces. Moreover, inspired by recent experiments on hybrid monolayer-Pt/WC catalysts, we study H adsorption on these hybrid surfaces. We consider both W and C terminations and vary the number of Pt layers. We predict that the H binding energy (HBE) plateaus rapidly with the number of Pt layers and that a monolayer of Pt on a WC substrate has a similar HBE to that of pure Pt. This corroborates the experimental observation that the two systems exhibit similar electrochemical activities. Increasing the number of Pt layers leads to a slight increase in the HBE and a projected decrease in catalytic activity. Through various electronic structure analyses, we show that the similarity in activities is due to an intrinsic alteration of the character of the Pt/WC surface rather than a similarity to the pure Pt surface. Our findings provide guidance for tuning parameters that affect catalytic activity by controlling WC surface termination and Pt overlayer thickness.
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U2 - 10.1149/2.0481607jes
DO - 10.1149/2.0481607jes
M3 - Article
AN - SCOPUS:84964588049
SN - 0013-4651
VL - 163
SP - F629-F636
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
IS - 7
ER -