Operando TEM Studies of Re@Cu2O-SnO2 catalysts during CO2 reduction reaction with optimized liquid flow configuration

The energy transition is nowadays a topic of huge attention, as a measure to face the global energy crisis and the more and more impacting climate change. In this framework, the production of carbon-based chemicals and fuels by exploiting anthropogenic CO2 is nowadays considered a way-out to leave the traditional oil-based technology. In fact, renewable and green approaches to CO2 valorisation are aimed at minimizing the worrying impact of its emission to the environment, and to drive the transition to a new circular economy approach in chemistry and energy production. A strategic method to reduce CO2
concentration in the atmosphere is to consider it as a valuable raw material, collecting it from industrials point sources and electrochemically reducing it into value-added products. This green approach can contribute to the development of alternative energetic vectors, or organic molecules normally derived from fossil resources. Among many products that can be obtained, which depend on the catalyst characteristics, reaction conditions and electrolyte, the CO2 reduction reaction (CO2RR) to carbon monoxide (CO) or formic acid (HCOOH) are up to now the most economically viable processes and can challenge conventional production routes [1]. In order to design efficient catalysts for CO2RR with high activity, selectivity and stability, it is important to understand the fundamental mechanisms involved in the electrochemical processes. In this context, in situ / operando characterization techniques provide insight into the correlation between physical-chemical properties and the electrochemical performance. Specifically, electrochemical liquid phase transmission electron microscopy (EC-LPTEM) yields temporally and spatially resolved morphological, structural and chemical information regarding catalytic materials under electrochemical stimulation [2]. Within this framework, in this paper, EC-LPTEM experiments on molecular Re@Cu2O/SnO2 catalysts for CO2RR are presented and compared to the lab-scale experiments.