Tuning proton-coupled electron transfer by crystal orientation for efficient water oxidization on double perovskite oxides

Abstract

Developing highly efficient and cost-effective oxygen evolution reaction (OER) electrocatalysts is critical for many energy devices. While regulating the proton-coupled electron transfer (PCET) process via introducing additive into the system has been reported effective in promoting OER activity, controlling the PCET process by tuning the intrinsic material properties remains a challenging task. In this work, we take double perovskite oxide PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ (PBSCF) as a model system to demonstrate enhancing OER activity through the promotion of PCET by tuning the crystal orientation and correlated proton diffusion. OER kinetics on PBSCF thin films with (100), (110), and (111) orientation, deposited on single crystal LaAlO 3 substrates, were investigated using electrochemical measurements, density functional theory (DFT) calculations, and synchrotron-based near ambient X-ray photoelectron spectroscopy. The results clearly show that the OER activity and the ease of deprotonation depend on orientation and follow the order of (100) > (110) > (111). Correlated with OER activity, proton diffusion is found to be the fastest in the (100) film, followed by (110) and (111) films. Our results point out a way of boosting PCET and OER activity, which can also be successfully applied to a wide range of crucial applications in green energy and environment.

Layered-perovskite oxides with in situ exsolved Co–Fe alloy nanoparticles as highly efficient electrodes for high-temperature carbon dioxide electrolysis

“…50 In contrast, Co and Fe in the as-prepared STCF were dominated by 2+ and 3+. 51–53 These XPS results further confirmed the exsolution of Co and Fe alloy metal nanoparticles on the surface after hydrogen reduction. Furthermore, the atomic ratio of Co 0 : Fe 0 in Co–Fe–STCF annealed at 900 °C for 1 hour is quantified to be 0.37 : 1 based on the Co 0 and Fe 0 peaks in the XPS spectra (Fig.…”

Activating lattice oxygen in NiFe-based (oxy)hydroxide for water electrolysis

“…(Supplementary note 3 , Supplementary Fig. 22 - 23 ) 8 , 9 , 38 . To further prove the impact of proton activity, the OER activity of NiFe and MoNiFe (oxy)hydroxide were also evaluated in the NaOD and NaOH solution.…”

Bifunctional electrochemical properties of La0.8Sr0.2Co0.8M0.2O3−δ(M = Ni, Fe, Mn, and Cu): efficient elemental doping based on a structural and pH-dependent study

“…In addition, Ir-and Ru-based catalysts have been known to be the most active catalysts for the OER but suffer from poor ORR activity. [1][2][3] Conversely, Pt-based catalysts are widely used for ORR but provide unsatisfactory OER performances. 4,5 In response, extensive research efforts have been made to explore non-precious metal-based bifunctional catalysts for the OER/ORR with high performances.…”