High‐Temperature CO2 Electrolysis in Solid Oxide Electrolysis Cells: Developments,Challenges, and Prospects

High‐temperature CO₂ electrolysis in solid‐oxide electrolysis cells (SOECs) could greatly assist in the reduction of CO₂ emissions by electrochemically converting CO₂ to valuable fuels through effective electrothermal activation of the stable C?O bond. If powered by renewable energy resources, it could also provide an advanced energy‐storage method for their intermittent output. Compared to low‐temperature electrochemical CO₂ reduction, CO₂ electrolysis in SOECs at high temperature exhibits higher current density and energy efficiency and has thus attracted much recent attention. The history of its development and its fundamental mechanisms, cathode materials, oxygen‐ion‐conducting electrolyte materials, and anode materials are highlighted. Electrode, electrolyte, and electrode–electrolyte interface degradation issues are comprehensively summarized. Fuel‐assisted SOECs with low‐cost fuels applied to the anode to decrease the overpotential and electricity consumption are introduced. Furthermore, the challenges and prospects for future research into high‐temperature CO₂ electrolysis in SOECs are included.     

LaxSr2-xFe1.5Ni0.1Mo0.4O6-δ对称电池电解CO2研究

固态氧化物电解池(SOECs)因较高的能量转化效率在电化学还原CO₂, 实现“碳中和”社会方面备受关注。与非对称电池结构相比, 对称SOECs的空气极和燃料极是相同或相近的材料, 可以减少界面种类, 改善电极与电解质的热膨胀匹配性, 简化电池的制备工艺。本研究合成了钙钛矿氧化物La_xSr_2-xFe_1.5Ni_0.1Mo_0.4O_6-δ (L_xSFNM, x=0.1、0.2、0.3、0.4), 作为固体氧化物电解池的对称电极用于评估纯CO₂的电化学还原性能。掺入La³⁺可以有效提高反应催化活性, 其中L_0.3SFNM为电极的电解池表现出最高的电化学性能, 800 ℃下, 在空气中的极化电阻为0.07 Ω∙cm², 在50% CO-50% CO₂中的极化电阻为0.62 Ω∙cm²。单电池L_0.3SFNM@LSGM|LSGM|L_0.3SFNM@LSGM在800 ℃和1.5 V电压下的电解电流密度为1.17 A∙cm^-2, 在初始的50 h CO₂短期电解测试中表现出优异的稳定性, 是一种理想的对称电极材料。     

Novel Molecular Doping Mechanism for n‐Doping of SnO2 via Triphenylphosphine Oxide and Its Effect on Perovskite Solar Cells

Molecular doping of inorganic semiconductors is a rising topic in the field of organic/inorganic hybrid electronics. However, it is difficult to find dopant molecules which simultaneously exhibit strong reducibility and stability in ambient atmosphere, which are needed for n‐type doping of oxide semiconductors. Herein, successful n‐type doping of SnO₂ is demonstrated by a simple, air‐robust, and cost‐effective triphenylphosphine oxide molecule. Strikingly, it is discovered that electrons are transferred from the R3P⁺? O^?σ‐bond to the peripheral tin atoms other than the directly interacted ones at the surface. That means those electrons are delocalized. The course is verified by multi‐photophysical characterizations. This doping effect accounts for the enhancement of conductivity and the decline of work function of SnO₂, which enlarges the built‐in field from 0.01 to 0.07 eV and decreases the energy barrier from 0.55 to 0.39 eV at the SnO₂/perovskite interface enabling an increase in the conversion efficiency of perovskite solar cells from 19.01% to 20.69%.