Recent ucb_chemistry_cbme_oapdeposits items

Operation-Induced BiVO4 Surface Reconstruction Modulates Photoelectrochemical Glycerol Photooxidation Stability and Activity

Thu, 20 Aug 2026 00:00:00 +0000

Abstract Operation-induced surface reconstruction of photoelectrodes is underexplored as a path to control stability and performance. We show how adaptive junctions form via surface reconstruction of BiVO4 during glycerol photooxidation and how these surfaces affect electrolyte-dependent kinetics and durability. Preferential V dissolution in both acidic and alkaline media forms a Bi-rich layer. In situ measurements through a dual-working-electrode platform quantify the changes in photovoltage and charge-transfer resistance derived from adaptive junction formation, while enabling quantitative separation of the driving forces for charge separation and interfacial catalysis. The reconstructed surface in acidic media improves hole-transfer kinetics, functions as a glycerol-oxidation catalyst, and imparts photostability. Surface reconstruction in alkaline media exhibits the opposite behavior, impeding hole injection. This instability is mitigated by trace Ni2+ ions, which drive in...

Polyketide synthase-based controlled synthesis of polycyclopropanated fuel molecules

Thu, 20 Aug 2026 00:00:00 +0000

Reducing carbon emissions from aviation and long-distance transportation sectors requires the development of sustainable biofuels with suitable energy density, freezing point, and other physical properties. We previously demonstrated biological production of high energy polycyclopropanated fatty acids (POP-FAs, class I) using an iterative polyketide synthase (iPKS) pathway in a Streptomyces host. Here, we used a computational model of fuel properties to identify chain length and cyclopropanation control as critical steps to engineer this iPKS for biofuel applications. We next explored the natural diversity of POP biosynthesis by investigating homologous pathways. Then, by in vivo gene exchange, we determined cyclopropanase (CP) catalysis to be key for POP-FA engineering. Leveraging both natural and engineered pathway product diversity, we demonstrate targeted production of improved POP-FAs, namely shortened POP-FAs with predicted superior freezing point properties for aviation,...

Low-voltage syngas synthesis via BPM electrolysis of CO 2 capture and aldehyde solution

Mon, 3 Aug 2026 00:00:00 +0000

A bipolar membrane electrolyzer coupling bicarbonate electrolysis with formaldehyde oxidation directly produces syngas (H 2 : CO = 1) at 1.7 V and 200 mA cm −2 with 200% combined Faradaic efficiency. We demonstrate an electrochemical syngas production platform that couples bicarbonate electrolysis with formaldehyde oxidation in a bipolar membrane electrode assembly. This strategy doubles syngas (CO + H 2 ) throughput compared to conventional CO 2 electrolysis by generating CO at the cathode and H 2 at the anode. The system achieves a full-cell voltage of 1.7 V while operating at an industrially relevant current density of 200 mA cm −2 . The system maintained a combined Faradaic efficiency of 200% over 8 hours. The process produces syngas with a 1 : 1 H 2 : CO ratio, aligning with downstream requirements for Fischer–Tropsch synthesis. We further investigated how Cu anode active sites and electrolyte composition affect formaldehyde oxidation activity. Our integrated electrolytic...

Structure of iridium oxide catalysts dictates performance differences for proton exchange membrane water electrolyzers

Fri, 31 Jul 2026 00:00:00 +0000

A systematic catalyst loading study reveals the higher catalytic activity of amorphous iridium oxide arises from bulk participation via suggested electrochemical descriptors, while identifying loading-independent intrinsic electrochemical properties. Proton exchange membrane water electrolyzers (PEMWEs) are promising zero-emission technologies. However, their high cost remains a barrier to widespread adoption. Iridium oxide is commonly used as an oxygen evolution reaction (OER) catalyst, and its cost and scarcity make it essential to reduce its loading while increasing its activity. Evaluation of iridium oxide activity should be carried out in the membrane electrode assembly (MEA) configuration to replicate realistic operating conditions. Herein, we present a comprehensive benchmarking framework to accurately evaluate the amorphous and crystalline iridium oxides at the MEA level. By systematically varying the catalyst loading, this study confirmed that each MEA was utilized...

Activating magnetite ores for aqueous ironmaking at high current densities

Fri, 31 Jul 2026 00:00:00 +0000

Low-temperature electrochemical cells reducing iron oxides to metal in alkaline electrolytes can support fully electrified steelmaking processes. Previous studies on these cells have primarily focused on high-surface-area hematite, Fe 2 O 3 , reactants... Low-temperature electrochemical cells reducing iron oxides to metal in alkaline electrolytes can support fully electrified steelmaking processes. Previous studies on these cells have primarily focused on high-surface-area hematite, Fe 2 O 3 , reactants whereas attempts to reduce suspensions of magnetite, Fe 3 O 4 —one of the two feedstocks for existing ironmaking reactors—have generally been limited to low rates of reaction (<30 mA cm -2 ). Here, we control the crystalline domain size of Fe 2 O 3 and Fe 3 O 4 particles in 10 M NaOH electrolytes to study how the nanoscale morphology of oxides controls the rate of electrochemical ironmaking. Rotating-ring disk electrode measurements of Fe 2+ , in-situ Raman spectroscopy of...

Correction to “Anions in Corrosion: Influence of Polymer Electrolytes on the Interfacial Ion Transfer Kinetics of Cu at Au(111) Surfaces”

Fri, 31 Jul 2026 00:00:00 +0000

Correction to “Anions in Corrosion: Influence of Polymer Electrolytes on the Interfacial Ion Transfer Kinetics of Cu at Au(111) Surfaces”

Anion-exchange membrane water electrolysis: insights from round-robin testing

Fri, 31 Jul 2026 00:00:00 +0000

As research and industrial interest in anion-exchange membrane water electrolysis (AEMWE) grows, there is an increasing need for reliable baselines and cross-lab validation of results. The wide variety of material sets and operating conditions under consideration for AEMWE has thus far limited efforts for standardization. In this study, round-robin testing was conducted in deionized water and KOH-based supporting electrolyte by 5 institutions from academia, national laboratories, and industry to provide baseline performance data and identify sources of cross-lab variability. Baseline membrane electrode assemblies were fabricated with commercial catalysts, membranes, and transport layers using standard techniques and tested using reagent-grade electrolytes, aiming for accessibility rather than state-of-the-art performance. From all tests, the average voltage at 1 A/cm2 was 2.72 ± 0.17 V and 1.87 ± 0.03 V in deionized water and 0.1 M KOH, respectively. The maximum in-house and cross-lab...

Anions in Corrosion: Influence of Polymer Electrolytes on the Interfacial Ion Transfer Kinetics of Cu at Au(111) Surfaces

Fri, 31 Jul 2026 00:00:00 +0000

The corrosion kinetics of metals in the presence of polymer electrolyteswhich are frequently used in devices for the electrochemical production of hydrogen, hydrocarbons, and alcoholsis convoluted by transport and ill-defined reactive interfaces that mask the fundamental reaction kinetics. Underpotential-deposited monolayers of Cu at Au(111) surfaces provide a structurally well-defined active site for interfacial ion transfer with a fixed number of sites available for adsorption. Here, we investigate the adsorption behavior of Cu at Au(111) surfaces across a series of sulfate and sulfonate electrolytes to understand how anion structure influences the kinetics of elementary interfacial ion-transfer reactions. The influence of anion structure is most significant at high adsorbate coverage, with similar adsorption isotherms and kinetics observed for sulfates and two molecular sulfonates. In contrast, a suspended perfluorosulfonic acid ionomer reduced both the equilibrium coverage...

Ion Dynamics and Polarizations in a Simulated Nanopore under Alternating Current Controls

Fri, 31 Jul 2026 00:00:00 +0000

Understanding ion transport through nanopores provides a central basis in advancing the design of molecular sensors or the preparation of biomimetic systems. Here we report a continuum modeling approach that introduces an alternating current field to investigate the competition between a surface-charge dominated electromigration process under a frequency induced ion dynamics at nanoscales. We highlight a transition from a surface-charge-dominated effect, where electric double layer impacts prevail, to bulk-like ion dynamics as pore dimensions approach the microscale. Results reveal that rapid electromigration dominates ion distribution at a millisecond time scale, generating transient, non-equilibrium concentration profiles. In contrast, lower frequency perturbations enable diffusion to equilibrate ion distributions within each cycle, establishing periodic quasi-steady states. The findings from this work highlight the interplay of ion selectivity and distribution by exploiting...

In-Situ tuning of Catalyst Surface Chemistry for Understanding Proton-Transfer in Bipolar Membranes