Development and Applications of Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) in Protonic Ceramic Cells

Abstract

Protonic ceramic cells (PCCs) are emerging as a versatile platform for power generation, hydrogen production, and electrochemical synthesis at intermediate temperatures (300–600 °C). While substantial progress has been achieved in materials development and cell performance, a fundamental understanding of proton transfer, hydration processes, and catalytic reaction mechanisms remains limited, particularly under realistic operating conditions. Addressing this gap is essential for rational design of electrodes and electrolytes with improved cell efficiency, product selectivity/yield, and long-term durability. This research proposal aims to establish diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) as a mechanistic and kinetic probe for key surface processes in PCCs. The proposed work systematically applies Operando DRIFTS to three representative challenges: (i) Time-resolved DRIFTS is used to quantify surface and near-surface proton kinetics in protonic ceramic electrolytes, enabling extraction of exchange rates, activation energies, and kinetic asymmetry among hydration, dehydration, and H2O/D2O isotope exchange processes; (ii) The impact of nickel in BaZr0.1Ce0.7Y0.1Yb0.1O3−δ protonic electrolyte on hydration behavior and isotope exchange dynamics is investigated using DRIFTS to clarify how Ni incorporation alters local proton transport environments and kinetics. (iii) DRIFTS is employed to elucidate catalytic reaction pathways during CO2 methanation in protonic ceramic electrochemical cells, with an emphasis on identifying surface intermediate and structure-activity relationships that govern methane selectivity; By integrating with complementary DRIFTS measurements and material characterizations, this research seeks to bridge the gap between macroscopic performance and microscopic proton behavior in PCCs. The outcomes will provide qualitative and quantitative insights into surface hydration and catalytic mechanisms of PCCs, offering guidance for materials optimization and cell design.