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The in situ exsolution technique of nanoparticles has brought new opportunities for the utilization of perovskite‐based catalysts in solid oxide cells. However, the lack of control over the structural evolution of host perovskites during the promotion of exsolution has restricted the architectural exploitation of exsolution‐facilitated perovskites. In this study, we strategically broke the long‐standing trade‐off phenomenon between promoted exsolution and suppressed phase transition via B‐site supplement, thus broadening the scope of exsolution‐facilitated perovskite materials. Using carbon dioxide electrolysis as an illustrative case study, we demonstrate that the catalytic activity and stability of perovskites with exsolved nanoparticles (P‐eNs) can be selectively enhanced by regulating the explicit phase of host perovskites, accentuating the critical role of the architectures of perovskite scaffold in catalytic reactions occurring on P‐eNs. The concept demonstrated could potentially pave the way for designing the advanced exsolution‐facilitated P‐eNs materials and unveiling a wide range of catalytic chemistry taking place on P‐eNs. [ABSTRACT FROM AUTHOR]

Perovskites with exsolved nanoparticles (P-eNs) have immense potentials for carbon dioxide (CO2) reduction in solid oxide electrolysis cell. Despite the recent achievements in promoting the B-site cation exsolution for enhanced catalytic activities, the unsatisfactory stability of P-eNs at high voltages greatly impedes their practical applications and this issue has not been elucidated. In this study, we reveal that the formation of B-site vacancies in perovskite scaffold is the major contributor to the degradation of P-eNs; we then address this issue by fine-regulating the B-site supplement of the reduced Sr2Fe1.3Ni0.2Mo0.5O6-δ using foreign Fe sources, achieving a robust perovskite scaffold and prolonged stability performance. Furthermore, the degradation mechanism from the perspective of structure stability of perovskite has also been proposed to understand the origins of performance deterioration. The B-site supplement endows P-eNs with the capability to become appealing electrocatalysts for CO2 reduction and more broadly, for other energy storage and conversion systems. The instability of perovskites with exsolved nanoparticles for CO2 electrocatalysis impedes their practical applications. Here, the authors show the formation of B-site vacancies in perovskite substrate as a major contributor to the degradation and report a strategy to enhance the stability of the perovskites at high voltages. [ABSTRACT FROM AUTHOR]

[Display omitted] • In species was integrated on CuO to directionally maximize CO selectivity using a facile method. • CO formation was initiated at an ultralow onset potential of −0.196 V vs. RHE. • A remarkably high CO Faraday efficiency of near-unity was achieved. • A slow reduction of CuO to metallic Cu caused by the In species guarantees an unprecedented stability for CO 2 RR. • The reasons credited for the enhanced CO 2 RR performance are systematically explored. CO 2 reduction reaction (CO 2 RR) is one of the most promising approaches to alleviating greenhouse gas effect and simultaneously producing value-added chemicals and has been widely studied in recent years. To this end, a composite of indium species on CuO (InO x @CuO) was facilely synthesized for CO 2 RR, and it is found that the selectivity of the target product could be accurately tuned through incorporating post-transition species with Cu-based materials; the desirable Faraday efficiencies of over 90%, with a maximum value of 97.8%, toward CO formation were achieved in a wide potential window from −0.3 to −0.7 V. Moreover, a high CO partial current density of 7.2 mA cm−2 and a long-term stability of 50 h with negligible degradation were obtained over InO x @CuO. More importantly, CO starts to be observed at an ultralow potential of −0.196 V, further confirming the excellence of InO x @CuO for CO 2 RR toward CO formation. The results demonstrate that the achieved superiority derives from the essential In species on CuO, which not only introduces more active sites, but also better stabilizes the key intermediates, accelerates electron transfer and increases CO 2 adsorption. [ABSTRACT FROM AUTHOR]

We report the preparation of an "all in one" wavy SnO 2 with abundant oxygen vacancies, grain boundaries and low-coordinated active sites (such as edge and corner sites), which simultaneously intensifies the adsorption and activation of CO 2 , facilitates electron transfer, therefore, improves the efficiency of CO 2 reduction reaction (CO 2 RR). • Wavy SnO 2 was used to electrochemical converse carbon dioxide into HCOOH for the first time. • Wavy SnO2 exhibits enhanced adsorption and activation ability of CO2 molecular and CO2•- intermediate. • Wavy SnO 2 with abundant oxygen vacancies, grain boundaries and low-coordinated active sites (such as edge and corner sites) is the reason for the enhanced CO 2 RR activity and selectivity. • Wavy SnO 2 shows a maximum FE HCOOH (87.4%) and EE HCOOH (57.5%) at -1.0 V vs. RHE. • Wavy SnO 2 enjoys the lower onset overpotential and higher HCOOH partial current density than the nanoparticle SnO 2. The tin oxide (SnO 2) based materials have emerged as one of the most promising candidates to highly electrolyze the carbon dioxide (CO 2) and produce formic acid. However, it still cannot meet the requirement for practical application because a substantial overpotential is needed to achieve a high HCOOH Faraday efficiency (FE) along with a large current density. In this work, we report the preparation of an "all in one" wavy SnO 2 having abundant oxygen vacancies, grain boundaries and low-coordinated active sites (such as edge and corner sites) by a facile yet simple one-pot hydrothermal strategy, which simultaneously intensifies the adsorption and activation of CO 2 , facilitates electron transfer and thus, improves the efficiency of CO 2 reduction reaction (CO 2 RR). Importantly, this study demonstrates a wavy SnO 2 (NW-SnO 2) with optimized surface structure for the significantly enhanced electrocatalytic reduction of CO 2 to HCOOH with maximum FE HCOOH = 87.4% and EE HCOOH = 57.5% at −1.0 vs V RHE. The synthesizing process reported herein is superior to a number of the current SnO 2 based electrocatalysts since it is much easier, more cost effective and benign, an apparent advantage in terms of its future large scale of applications. This study could be extended to much abroad applications and serves as a guide to synthesize other metallic oxide based catalysts for CO 2 RR by tuning surface structure. [ABSTRACT FROM AUTHOR]