Francisco Pelayo García de Arquer

A dual-function porous layer suppresses carbonate formation by restricting electrolyte convection, enabling alkaline CO ₂ electrolysis for 500 h with 80% C ₂ -product selectivity at 2.30 V and the lowest energy cost reported to date.

The electrooxidation of glycerol presents a promising route for upgrading a biodiesel byproduct into high‐value chemicals while lowering the energy cost of electrochemical hydrogen production, but its mechanistic understanding remains incomplete. This work investigates the influence of temperature and catalyst composition on glycerol electrooxidation using three distinct electrocatalysts: first‐row transition‐metal NiCo oxide, noble metal AuIn alloy, and hybrid PdNi alloy. Electrochemical, in situ UV–vis reflectance and in situ Raman measurements reveal catalyst‐specific oxidation mechanisms: an oxyhydroxide‐mediated path for NiCo, an adsorbed hydroxide‐mediated path for AuIn which suffers from inhibition, and a dual mechanism for PdNi. Oxyhydroxide mechanisms favor formic acid, whereas adsorbed hydroxide pathways selectively promote C ₃ products such as glyceric acid and dihydroxyacetone. Flow cell electrolysis across a range of temperatures and flow rates relevant to industrial application shows that elevated temperature enhances reaction rates and mitigates catalyst inhibition, a relevant effect for the hybrid catalyst. These findings provide key mechanistic insights and practical guidelines for optimizing continuous‐flow glycerol electrooxidation systems.

The production of hydrogen via acidic water electrolysis requires efficient oxygen evolution reaction (OER) at high current densities. However, this is often limited by oxygen bubble accumulation, which blocks active sites and restricts water access. Although bubble release and water access are closely linked, these interfacial processes are rarely controlled together. We engineer a ruthenium oxide–cerium oxide (RuOx–CeOx) catalyst where CeOx is observed to modulate surface oxygen vacancies during operation, enhancing water availability and promoting bubble detachment in RuOx. In situ X-ray absorption studies show that CeOx dynamically facilitates the formation of surface oxygen vacancies, and Raman spectroscopy indicates improved electrolyte wetting under applied potentials. Simulations reveal that oxygen-depleted RuOx surfaces favor water accumulation, thereby facilitating the initiation of OER. This results in distinct bubble dynamics with a four-fold reduction in median bubble contact area and lower overpotentials at high current densities in RuOx–CeOx compared to RuOx. Implementation in a proton exchange membrane water electrolyzer achieves a 0.1 V reduction in full-cell potential at 1 A·cm–2, linking surface chemistry to device-level outcomes.

The bottom-up assembly of colloidal quantum dots (CQDs) into superlattice structures is attractive for leveraging nanocrystal quantum features into films and optoelectronic devices. However, current CQD superlattices often require tedious control of the assembly kinetics, and they suffer from either excessively long interfacial distances, which impede carrier transport, or facet fusion, which brings high defect density. These hinder CQD superlattice applications in optoelectronic devices, where low defect density and large carrier diffusion lengths are essential. Herein, inspired by the growth of a two-dimensional (2D) perovskite layer, a class of aromatic organic cation ligands is adopted to stabilize CQDs and induce close and ordered packing of CQDs into a superlattice netted by an organic metal halogenide (QD@OMH), giving rise to a high carrier diffusion length (>250 nm) for lead sulfide (PbS) CQD film. The superlattice-based infrared photodetectors achieve a responsivity of 0.663 A W–1 at 1560 nm and an order-of-magnitude reduction in noise current density, yielding a detectivity exceeding 1013 Jones. Furthermore, the infrared light-emitting diodes achieve a high radiance (22.4 W sr–1 m–2) and an operational T90 lifetime exceeding 200 h under continuous operation at peak luminance.

Low-temperature CO₂ electroreduction (CO₂eR) to syngas offers tunable H₂:CO ratios and a renewable route to decarbonized syngas production, yet catalyst-level advances rarely translate to scalable, durable systems. This review addresses that disconnect with a systems-engineering perspective. We first establish the component foundations, electrolytes, membranes, and cell architectures of flow cells and zero-gap membrane electrode assembly (MEA) electrolyzers, together with integrated versus decoupled syngas production modes, then analyze the engineering failure modes that dominate at scale: non-uniform current distribution, localized hotspots, electrode flooding, salt precipitation, and thermal gradients. Single-pass CO₂ conversion efficiency (SPCE) is introduced as a co-equal metric alongside Faradaic and energy efficiency (FE/EE). Original contributions include a standardized accelerated stress test (AST) protocol, a lifecycle sustainability assessment (LCSA) framework with quantitative carbon footprint benchmarking, a mitigation strategy compatibility matrix, and three-benchmark design pathways targeting high EE, high stability, and high SPCE, providing an actionable systems-engineering roadmap toward CO₂eR systems sustaining >5000 h at industrially relevant current densities.

Electrochemical CO₂ reduction (CO₂R) in acid may enable high carbon utilization but faces selectivity challenges, particularly from the Hydrogen Evolution Reaction (HER). While the source of protons and cation concentrations play a role in this balance, the role of anions remains underexplored. Here, we combine in situ surface-enhanced Raman Spectroscopy during CO₂R in acid with theoretical simulations to investigate the role of anionic species over copper gas diffusion electrodes at application-relevant current densities (up to 0.2 A·cm^-2) and performance. Our observations reveal that sulfate adsorption inhibits CO₂R at low pH and delays CO₂R intermediate formation, which is enabled by hydroxyl species coadsorption. Such competition regulates *CO stabilization and the balanced *CO coverage needed to favor the formation of multicarbon products. These results shed light on how anion interactions govern CO₂R selectivity under acidic conditions and their impact on overpotentials, offering guidance on catalyst-electrolyte interface design.