Authors: Joel A. Haber
Source: ECS Meeting Abstracts (article, 2025-07-11)
Field: Materials Science — Materials Chemistry

(<i>Invited) </i>High Throughput Experimentation for Solar Fuels Materials and Methods—12 Years of Deployment and Discovery The high throughput experimentation group for solar fuels at Caltech has deployed and evolved a pipeline for (photo-)electro-catalyst and photoabsorber materials discovery and optimization, over the past decade. Utilizing diverse synthesis (including inkjet printing and reactive co-sputtering) and processing (rapid thermal processing and varied thermal profiles in inert and reactive atmospheres) methods, 1 with detailed tracking of sample provenance, 2,3 several hundred thousand precious-metal-free samples were characterized as dark electrocatalysts for the oxygen evolution reaction (OER), from pH 1 to 14, 4–7 photoanodes, 8–10 and photoanode assemblies. 11 Investigation of CO 2 reduction catalysts required the development of sealed-gasket cells to enable longer duration electrolysis experiments to build up product concentrations to detectable limits coupled to robotic syringe sampling of gas and liquid aliquots followed by injections for GC, HPLC and ICPM analysis. 12 Continued evolution of this system has focused on investigation of the impact of electrolyte engineering and operating temperature on product distribution and electrode durability/corrosion. 13 Both electrocatalytic cathodes and photocathodes based on thin film chalcopyrite semiconductors (CuGa 3 Se 5 , Cu(In,Ga)Se 2 , and ZnTe) have been investigated for activity, durability, and composition-dependent mechanistic pathways. 14 Recently demonstrated instruments are dedicated to dynamic alteration of electrolyte compositions with varied electrochemical profiles and temperature to investigate and understand electrochemical corrosion in photoanodes and OER catalysts. 15 The use of rapid, inexpensive optical data collection as a function of composition has been validated as a method of identifying phase behavior and compositions and processing conditions for focused attention for synthesis and structural characterization by X-ray diffraction and spectroscopy. 16 Extension of these fast optical measurements to photoelectrochemical conditions to identify electrolyte and electrochemical conditions producing spectroscopic/optical changes potentially attributable to corrosion process is being implemented in a cloud-based autonomous instrument with machine-learning guided variation in experimental parameters. 17 Other instruments recently demonstrated include dynamic testing of CO 2 -sorption materials. 18 Early Lab-view based instrument automation has been supplanted by Python-based Hierarchical Experimental Laboratory Automation and Orchestration with asynchronous programming (HELAO-async) and event-driven automation 19 to facilitate machine-learning guided, dynamic variation in experimental conditions and composition selection in cloud-based and autonomous instruments. Gregoire, Boyd, Guevarra, Haber, Jones, Kan, Marcin, Newhouse, Shinde, Soedarmadji, Suram, Zhou Chapter 9:High Throughput Experimentation for the Discovery of Water Splitting Materials. In Integrated Solar Fuel Generators ; 2018; pp 305–340. Statt, Rohr, Guevarra, Suram, Morrell, Gregoire, Sci. Data 2023 , 10 , 184. Statt, Rohr, Guevarra, Breeden, Suram, Gregoire, Digit. Discov. 2023 , 2 , 909. Haber, Cai, Jung, Xiang, Mitrovic, Jin, Bell, Gregoire, Discovering Ce-Rich Oxygen Evolution Catalysts, from High Throughput Screening to Water Electrolysis. Energy Environ. Sci. 2014 , 7 , 682. Stein, Guevarra, Shinde, Jones, Gregoire, Haber, Functional Mapping Reveals Mechanistic Clusters for OER Catalysis across (Cu–Mn–Ta–Co–Sn–Fe)Ox Composition and PH Space. Mater. Horiz. 2019 . https://doi.org/10.1039/C8MH01641K. Haber, Anzenburg, Yano, Kisielowski, Gregoire, Multiphase Nanostructure of a Quinary Metal Oxide Electrocatalyst Reveals a New Direction for OER Electrocatalyst Design. Adv. Energy Mater. 2015 , https://doi.org/10.1002/aenm.201402307. Zhou, Shinde, Montoya, Singh, Gul, Yano, Ye, Crumlin, Richter, Cooper, Stein, Haber, Persson, Gregoire, Rutile Alloys in the Mn–Sb–O System Stabilize Mn 3+ To Enable Oxygen Evolution in Strong Acid. ACS Catal. 2018 , 8 , 10938. Newhouse, Guevarra, Umehara, Reyes-Lillo, Zhou, Boyd, Suram, Cooper, Haber, Neaton, Gregoire, Combinatorial Alloying Improves Bismuth Vanadate Photoanodes via Reduced Monoclinic Distortion. Energy Environ. Sci. 2018 . Yan, Yu, Suram, Zhou, Shinde, Newhouse, Chen, Li, Persson, Gregoire, Neaton, Solar Fuels Photoanode Materials Discovery by Integrating High-Throughput Theory and Experiment. Proc. Natl. Acad. Sci. 2017 . Zhou, Shinde, Guevarra, Richter, Stein, Wang, Newhouse, Persson, Gregoire, Combinatorial Screening Yields Discovery of 29 Metal Oxide Photoanodes for Solar Fuel Generation. J. Mater. Chem. A 2020 . Guevarra, Shinde, Suram, Sharp, Toma, Haber, Gregoire, Energy Environ. Sci. 2016 , 9 , 565. Lai, Watkins, Rosas-Hernández, Thevenon, Heim, Zhou, Wu, Peters, Gregoire, Agapie, ACS Cent. Sci. 2021 , 7 , 1756. Watkins, Lai, Schiffer, Canestraight, Atwater, Agapie, Peters, Gregoire, ACS Energy Lett. 2024 , 9 , 1440. Lai, Watkins, Muzzillo, Richter, Kan, Zhou, Haber, Zakutayev, Peters, Agapie, Gregoire, ACS Energy Lett. 2022 , 1195. Kan, Guevarra, Zhou, Jones, Lai, Richter, Gregoire, ChemCatChem 2024 , 16 , e202301300. Yang, Haber, Armstrong, Yang, Kan, Zhou, Richter, Roat, Wagner, Coram, Berndl, Riley, Gregoire, Proc. Natl. Acad. Sci. 2021 , 118 . Guevarra, Kan, Lai, Jones, Zhou, Donnelly, Richter, Stein, Gregoire, Orchestrating Nimble Experiments across Interconnected Labs. Digit. Discov. 2023 , 2 (6), 1806. Jones, Lai, Kan, Guevarra, Haber, Ramirez, Zito, Li, Yang, Appel, Gregoire, Accelerated Screening of Carbon Dioxide Capture by Liquid Sorbents. Digit. Discov. 2024 , 3 , 674. Statt, Rohr, Guevarra, Suram, Gregoire, Event-Driven Data Management with Cloud Computing for Extensible Throughput ; Software deployment ; Data science ; Nanotechnology ; Engineering ; Computer science ; Materials science ; Telecommunications ; Software engineering ; Wireless Nuclear Materials and Properties