Synchrotron based operando surface X‐ray scattering study towards structure–activity relationships of model electrocatalysts

Andrey Goryachev,Francesco Carlà,Jan P Hofmann,Willem G Onderwaater,Philipp P T Krause,Roberto Felici,Jakub Drnec,Ad H Wonders,Emiel J M Hensen

doi:10.1002/slct.201600355

Abstract

AbstractA novel combination of Surface X‐ray Scattering techniques (SXS), i. e. GISAXS (Grazing‐Incidence Small‐Angle X‐Ray Scattering), XRR (X‐Ray Reflectivity) and SXRD (Surface X‐Ray Diffraction) alongside with simultaneous detection of gaseous products by OLEMS (On‐Line Electrochemical Mass Spectrometry) has been applied to study under operando conditions structure‐activity relationships of a Pt model electrocatalyst. The SXS‐OLEMS combination is able to follow dynamic changes in surface morphology and crystallography during water electrolysis. To showcase the combined SXS‐OLEMS setup for operando studies of electrode transformations, H2 and O2 evolution reactions (HER and OER) on a Pt model electrocatalyst and their dependence on type and degree of surface roughening have been investigated.

Highlights

Efficient electrocatalysts for water splitting are a crucial ingredient to the successful implementation of chemical energy conversion for the storage of intermittently available renewable energy in the form of gaseous or liquid fuels
In the cyclic voltammograms of the roughened surface, one can observe the formation of reversible features at + 0.26 V, + 0.20 V and + 0.05 V corresponding to underpotential adsorption of hydrogen on Pt(100), (110) and (111) facets followed by a sharp cathodic peak of H2 evolution starting at 0.00 V (Figure 1a).[4]
Increasing EOER of the roughening CV sequence leads to a negative shift of the oxide reduction peak (ORP) position by 110 mV accompanied by an increase of the ORP peak area

Summary

Introduction

Efficient electrocatalysts for water splitting are a crucial ingredient to the successful implementation of chemical energy conversion for the storage of intermittently available renewable energy in the form of gaseous or liquid fuels. E. GISAXS (Grazing-Incidence Small-Angle X-Ray Scattering), XRR (X-Ray Reflectivity) and SXRD (Surface X-Ray Diffraction) alongside with simultaneous detection of gaseous products by OLEMS (On-Line Electrochemical Mass Spectrometry) has been applied to study under operando conditions structure-activity relationships of a Pt model electrocatalyst.

Results

Conclusion