# Linking electrocatalytic turnover to elementary step rates in hydrocarbon fuel oxidation

## TL;DR

The paper shows how to improve propane fuel oxidation on platinum by understanding and resolving conflicts between different reaction steps.

## Contribution

The study introduces a step-resolved method to link electrocatalytic turnover rates to individual reaction steps in propane oxidation.

## Key findings

- Low propane oxidation activity on Pt is due to mismatched optimal potentials for adsorption, conversion, and CO oxidation.
- Applying alternating potentials improves overall reaction rates by optimizing individual steps separately.
- The step-resolved approach provides a framework for designing better electrocatalysts for complex reactions.

## Abstract

Maximizing steady-state turnover rates is a central goal in electrocatalysis research, but improving one reaction step often impedes others. Navigating these trade-offs requires methods that systematically reveal how a single parameter change affects all key steps of a reaction mechanism. Here, we use electrochemical mass spectrometry to determine the potential-dependent rates of each principal step in propane oxidation on Pt and directly relate them to the steady-state turnover rate. Our analysis reveals that low steady-state activity arises from a mismatch between the optimal potentials for adsorption, conversion, and *CO oxidation. By applying alternating potentials to individually optimize adsorption and oxidation, we overcome this limitation and achieve rates exceeding those under constant-potential operation. This step-resolved approach clarifies how individual processes interact to govern overall activity and provides a framework for the rational design of electrocatalysts carrying out complex reactions at steady-state.

The electrocatalytic oxidation of propane fuel is slow on Pt. By analyzing the rate of its individual steps, the authors show that slow propane oxidation is caused by a mismatch between the electrode potentials that promote propane adsorption, conversion of intermediates, and oxidation to CO2.