# Nonoxidative coupling of methane to ethane over a Pd–Bi deposited titania photocatalyst in a flow reactor

## TL;DR

A new photocatalyst using Pd–Bi on TiO2 efficiently converts methane into ethane with high selectivity.

## Contribution

A Pd–Bi/TiO2 photocatalyst achieves high ethane selectivity through a synergistic effect of Pd and Bi.

## Key findings

- A stable ethane formation rate of 5.8 µmol h−1 was achieved with 99% selectivity.
- Pd–Bi alloy species formed during photodeposition enhance ethane selectivity.
- The Pd–Bi/TiO2 catalyst outperforms Au/TiO2 and Pd–Bi/Ga2O3 under the same conditions.

## Abstract

Photocatalytic nonoxidative coupling of methane (photocatalytic NOCM) is a unique strategy for directly converting methane into more valuable C2 hydrocarbons like ethane and ethene at lower temperatures compared to traditional thermo-catalytic methods. In the current study, we developed a Pd–Bi/TiO2 photocatalyst prepared by a simultaneous photodeposition (PD) method. Under the present conditions, a stable ethane formation rate of 5.8 µmol h−1 was achieved with 99% ethane selectivity, which is significantly higher than that of previously reported photocatalysts, such as Au/TiO2 or Pd–Bi/Ga2O3 under the same reaction conditions. Part of the deposited Bi under PD conditions partially alloyed with Pd to form Pd–Bi alloy species in the case of the bi-metallic co-catalyst, which are proposed to be responsible for the higher selectivity towards ethane. The synergistic effect of Pd and Bi was studied experimentally.

A Pd–Bi bi-metallic co-catalyst offers highly selective non-oxidative coupling of methane over a TiO2 photocatalyst.