OD + CO -> D + CO2 Branching Kinetics Probed with Time-Resolved Frequency Comb Spectroscopy

TL;DR

This study employs time-resolved frequency comb spectroscopy to measure the kinetics and branching ratios of the OD+CO reaction, revealing detailed insights into product formation rates and pressure dependence relevant to atmospheric and combustion chemistry.

Contribution

It provides the first direct measurements of the activated product channel D+CO2 and absolute branching yields for OD+CO reactions using TRFCS.

Findings

Measured formation rate of D+CO2 at room temperature.

Determined pressure and bath gas dependence of product channels.

Quantified absolute yields of branching pathways.

Abstract

Time-resolved direct frequency comb spectroscopy (TRFCS) was used to study the kinetics of the deuterated analogue of the OH+CO->H+CO2 reaction, which is important for atmospheric and combustion chemistry. Complementing our recent work on quantifying the formation rate of the transient trans-DOCO radical, we report measurements of the kinetics of the activated product channel, D+CO2, at room temperature. Simultaneous measurements of the time-dependence of OD and CO2 concentrations allowed us to directly determine the formation rate, branching yield, and dependence on pressure and bath gas of the activated product. Together with the trans-DOCO formation rate, these new measurements provide absolute yields of branching channels for both products of OD+CO in the low-pressure limit.