7 Search Results

The sustainability potential of carbon capture, concentration, and utilization technologies motivates accelerated discovery of carbon dioxide sorbents, for which we present a high throughput screening instrument.

Abstract Operational durability is poorly characterized by traditional (photo)electrocatalyst discovery workflows, creating a barrier to scale‐up and deployment. Corrosion is a prominent degradation mechanism whose thermodynamics depend on the concentration of corrosion products in electrolyte. We present an automated system for characterizing the equilibration of (photo)electrodes with dissolved metals in electrolyte for a given electrode, pH, and electrochemical potential. Automation of electrode selection, electrolyte preparation, and electrolyte aliquoting enables rapid identification of self‐passivating electrodes and estimation of the equilibrium dissolved metals concentrations. The technique is demonstrated for metal oxide photoanodes in alkaline electrolyte, where BiVO ₄ is found to continuallymore » corrode, in agreement the literature. An amorphous Ni−Sb−O photoanode is found to passivate with a Ni‐rich coating on the order of 1 monolayer with less than 1 μM total dissolved metals in electrolyte, demonstrating its suitability for durable photoelectrochemical operation. The automation and throughput of the instrument are designed for incorporation in accelerated electrocatalyst discovery workflows so that durability can be considered on equal footing with activity.« less

Human researchers multi-task, collaborate, and share resources. HELAO-async is a multi-workflow automation software that helps realize these attributes in materials acceleration platforms.

Electrochemical CO₂ reduction to valuable products is a centerpiece of future energy technologies that relies on identification of new catalysts. Here, we present accelerated screening of Cu bimetallic alloys, revealing remarkable sensitivity to alloy concentration that indicates the migration of alloying elements to critical sites for hydrocarbon formation.

Identifying new catalyst materials for complex reactions such as the electrochemical reduction of CO₂ poses substantial instrumentation challenges due to the need to integrate reactor control with electrochemical and analytical instrumentation. Performing accelerated screening to enable exploration of a broad span of catalyst materials poses additional challenges due to the long time scales associated with accumulation of reaction products and the detection of the reaction products with traditional separation-based analytical methods. The catalyst screening techniques that have been reported for combinatorial studies of (photo)electrocatalysts do not meet the needs of CO₂ reduction catalyst research, prompting our development of a newmore » electrochemical cell design and its integration to gas and liquid chromatography instruments. To enable rapid chromatography measurements while maintaining sensitivity to minor products, the electrochemical cell features low electrolyte and head space volumes compared to the catalyst surface area. Additionally, the cell is operated as a batch reactor with electrolyte recirculation to rapidly concentrate reaction products, which serves the present needs for rapidly detecting minor products and has additional implications for enabling product separations in industrial CO₂ electrolysis systems. To maintain near-saturation of CO₂ in aqueous electrolytes, we employ electrolyte nebulization through a CO₂-rich headspace, achieving similar gas-liquid equilibration as vigorous CO₂ bubbling but without gas flow. The instrument is demonstrated with a series of electrochemical experiments on an Au-Pd combinatorial library, revealing non-monotonic variations in product distribution with respect to catalyst composition. The highly integrated analytical electrochemistry system is engineered to enable automation for rapid catalyst screening as well as deployment for a broad range of electrochemical reactions where product distribution is critical to the assessment of catalyst performance.« less

Identification of stable electrocatalysts for the oxygen evolution reaction (OER) remains a primary challenge in materials for energy. The pH-dependent activity is known for very few catalysts, prompting our exploration of a broad range of catalysts using high throughput experiments and data science. This approach enables the largest screening of OER activity and operational stability to date, as illustrated through investigation of the (Cu-Mn-Ta-Co-Sn-Fe)O_x composition space as 15 unique quaternary composition spaces. In total 2121 compositions are tested between pH 3 and 13, creating an extensive dataset whose interpretation requires development and application of data science to provide insights thatmore » are both beyond the standard composition-activity relationships and beyond human interpretation due to the dimensionality of the dataset. In this work, three distinct classes of OER catalysts are identified with respect to pH-dependent activity and stability. The large-scale screening reveals a new class of Co-rich OER catalysts that can be compositionally tailored to a specified pH and perform on par with state-of-the-art acid OER catalysts.« less