Alternative Energy Technologies Fuel Cells Allan J Jacobson

Alternative Energy Technologies: Fuel Cells Allan J. Jacobson Center for Materials Chemistry University of Houston 3/7/2021 A. J. Jacobson – CMC-UH 1

Future Fuels and Electricity • Now: – Fossil fuels: natural gas, oil, coal – Gas, steam turbines, combined cycle • Intermediate: – – – • Hydrogen from fossil fuels Fuel cells and new processes Distributed systems Superconducting transmission lines Future – Nuclear – Solar – Hydrogen from water • Electrolysis • Thermal from HT nuclear reactors • Photo-electrolysis – Renewables – ‘Supergrid’ 3/7/2021 A. J. Jacobson – CMC-UH 2

Key Drivers 3/7/2021 A. J. Jacobson – CMC-UH 3

Sources of Hydrogen 3/7/2021 A. J. Jacobson – CMC-UH 4

What is a Fuel Cell? 3/7/2021 A. J. Jacobson – CMC-UH 5

Fuel Cell Operation 500 – 1000 °C porous cathode electrolyte/membrane Cathode, an anode, and an electrolyte sandwiched between the two. Oxygen from the air flows through the cathode A fuel gas containing hydrogen, such as methane, flows past the anode. Oxygen ions migrate through the electrolyte and react with the hydrogen to form water Water reacts with the methane fuel to form carbon dioxide and hydrogen. Electrons from the electrochemical reaction flow from anode to cathode through an external load 3/7/2021 A. J. Jacobson – CMC-UH 6

Advantages of Fuel Cells • • 3/7/2021 High efficiency Modular Quiet Non Polluting - no NOx Distributed Combined heat and power Load flexible A. J. Jacobson – CMC-UH 7

Fuel Cell History 3/7/2021 A. J. Jacobson – CMC-UH 8

Fuel Cell History 3/7/2021 A. J. Jacobson – CMC-UH 9

Fuel Cell Types I Alkaline (AFC) developed for the Apollo program Polymer membrane (PEMC) leading candidate for transportation Phosphoric acid (PAFC) 200 k. W units commercially available for combined heat and power (CHP) Molten carbonate (MCFC) and solid oxide (SOFC) can work directly with hydrocarbon fuels – 200+k. W demonstration units Taken from B. C. H. Steele & A. Heinzel, Nature, 414 (2001) 345 3/7/2021 A. J. Jacobson – CMC-UH 10

Fuel Cell Types II Taken from B. C. H. Steele & A. Heinzel, Nature, 414 (2001) 345 3/7/2021 A. J. Jacobson – CMC-UH 11

PEMFC • Electrodes (anode and the cathode) separated by a polymer membrane electrolyte. • Each of the electrodes is coated on one side with a thin platinum catalyst layer. • The electrodes, catalyst and membrane form the membrane electrode assembly. • Hydrogen and air are supplied on either side through channels formed in the flow field plates Ballard® fuel cell 3/7/2021 A. J. Jacobson – CMC-UH 12

Advanced Fuel Cell Electrodes-PEM • % Anode = 0. 35 mg/cm 2 Pt Loading % Anode = 0. 72 mg/cm 2 catalyst loading 140 1. 0 120 0. 8 100 80 0. 6 60 0. 4 40 0. 2 20 0. 0 0 50 100 150 200 250 300 350 400 450 500 550 Current Density (m. A/cm 2) 3/7/2021 A. J. Jacobson – CMC-UH 13 0 600 Power Density, (m. W/cm 2) • A current DOE target is to develop alternative electrodes to replace the Pt and Pt-Ru electrodes that are used as cathode and anode electrocatalysts in PEM fuel cells. Ideally the anode catalyst would be tolerant to CO and S present in the hydrogen fuel. The figure shows a new class of non-Pt electrocatalysts that have activity comparable to Pt as shown by the performance of cell with the new catalyst as the anode. Voltage (V) •

SOFC Cathode Interconnection Electrolyte Anode (La, Sr)Mn. O 3 (La, Sr)Cr. O 3 8%Y 2 O 3 -Zr. O 2 Ni/ 8%Y 2 O 3 -Zr. O 2 1. 5 m extruded tubular (2. 2 mm) porous cathode plasma spraying (85 m) thick-film (30– 40 m) porous layer (100 m) by a slurry-spray process Siemens Westinghouse fuel cell 3/7/2021 A. J. Jacobson – CMC-UH 14

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Future Applications Application Size (k. W) Fuel cell Power systems for portable electronic devices 0. 001– 0. 05 PEMFC DMFC SOFC hydrogen methanol Micro-Combined Heat and Power 1– 10 PEMFC SOFC LPG Natural gas, LPG Auxiliary power units 1– 10 SOFC LPG Distributed Combined Heat 50– 250 and Power PEMFC MCFC SOFC natural gas City buses 200 PEMFC hydrogen Large power units 1000– 10, 000 SOFC/GT natural gas 3/7/2021 A. J. Jacobson – CMC-UH Fuel 18

Technical Challenges Many Challenges in Materials and Materials Processing – CO tolerant electrocatalysts – Better membranes for PEMFC and DMFC – Intermediate temperature high performance electrodes – Low cost fabrication processes for SOFC – New materials! 3/7/2021 A. J. Jacobson – CMC-UH 19

Core Technology Program Participants: Gas Technology Institute – Des Plaines, IL Georgia Tech Research – Atlanta, GA Montana State University – Bozeman, MT Nex. Tech Materials, Ltd – Worthington, OH Northwestern University – Evanston, IL Southwest Research Institute – San Antonio, TX Texas A&M University – College Station, TX University of Florida – Gainesville, FL University of Illinois – Chicago, IL University of Houston – Houston, TX University of Missouri – Rolla, MO University of Pittsburgh – Pittsburgh, PA University of Utah – Salt Lake City, UT University of Washington – Seattle, WA Virginia Tech – Blacksburg, VA Current Industrial Teams Argonne National Laboratory Lawrence Berkeley National Laboratory Los Alamos National Laboratory National Energy Technology Laboratory Oak Ridge National Laboratory Pacific Northwest National Laboratory Sandia National Laboratories 3/7/2021 A. J. Jacobson – CMC-UH 20

Water Electrolysis 3/7/2021 A. J. Jacobson – CMC-UH 21

Sources of Hydrogen 3/7/2021 A. J. Jacobson – CMC-UH 22

Hydrogen Production CO 2 Sequestration Membrane reactor CO 2 +H 2 Water Gas Shift Reactor CO +H 2 CO 2 Hydrogen Separation Device (PSA, HTM) H 2 Fuel Cells 3/7/2021 A. J. Jacobson – CMC-UH 23