University of Puerto Rico — Direct Ammonia Alkaline Fuel Cell (DAAFC)¶
Type: Academic Electrochemistry Research Group
PI: Carlos R. Cabrera Martinez (Professor and Chair, Chemistry & Biochemistry, UTEP — formerly UPR-Río Piedras)
Co-Is: Harry Rivera, Carlos Cabrera
Collaborators: Faraday Technology (bio-electrochemical process)
Outcome Category: FO → ISS Flight (AELISS on NG-14, Oct 2020) + Publications
Investigated: Session 27, 2026-04-06
Last updated: Session 75, 2026-04-07
Summary¶
Carlos Cabrera's electrochemistry group at UPR-Río Piedras used FO parabolic flights across 2 projects to study ammonia oxidation in microgravity — a critical reaction for both fuel cell energy production and ECLSS water reclamation. The technology converts ammonia (a toxic wastewater component) into nitrogen while generating electrical energy, addressing two problems simultaneously. The FO data directly led to development of AELISS (Ammonia Electrooxidation Lab at the ISS), an autonomous electrochemical system that met NASA ISS requirements, published in npj Microgravity (2023). Cabrera has since moved from UPR to UTEP, continuing the research program. TechPort shows an "Advanced To" outcome. This is a genuine FO→ISS escalation for ECLSS technology.
FO Projects¶
| Project | Title | TRL | Period | Status |
|---|---|---|---|---|
| T0040-P | DAAFC (predecessor) | — | Earlier | Completed |
| 91638 | DAAFC under Microgravity Conditions | 6 → 7 | 2013-06 – 2016-01 | Completed |
TechPort outcome: "Advanced To" (2013-08-01, partner: Other)
What Was Tested¶
Direct Ammonia Alkaline Fuel Cell (DAAFC): An electrochemical system using nanocatalysts (platinum nanoparticles on mesoporous carbon supports) to oxidize ammonia in an anion exchange membrane fuel cell. The process: 1. Oxidizes ammonia to nitrogen (removing a toxic waste product from water) 2. Generates electrical energy as a byproduct 3. Produces clean water
Microgravity challenge: Electrochemical reactions involving gas-liquid interfaces behave differently in microgravity. Bubble formation, mass transport, and electrode surface dynamics all change without gravity-driven convection. FO parabolic flights provided the first data on DAAFC performance in these conditions.
Key finding: Microgravity affects chronoamperometric ammonia oxidation — the team had to search for catalysts that could reduce or counter the loss of oxidation current density in microgravity.
Downstream Impact¶
AELISS — ISS Flight on NG-14 (npj Microgravity 2023)¶
CORRECTION (Session 55): AELISS was not merely an ISS-qualified prototype — it actually launched to the ISS on Cygnus CRS-14/NG-14 (Antares, October 1, 2020) and performed autonomous ammonia oxidation experiments in a 2U NanoRacks module. The key finding: the AOR cyclic voltammetric peak was observed in microgravity but showed ~70% current density decrease (69–74% range) compared to ground measurements, attributed to the buoyancy effect on gas-liquid mass transport. This confirmed the FO parabolic flight prediction that microgravity significantly impairs electrochemical ammonia oxidation kinetics — a critical design input for any ECLSS-scale ammonia remediation system.
Cabrera's group published these results in "Autonomous electrochemical system for ammonia oxidation reaction measurements at the International Space Station" in npj Microgravity (Nature, 2023) (DOI: 10.1038/s41526-023-00265-4).
Publications¶
- Cabrera et al., Acta (2012): "Microgravity effects on the electrochemical oxidation of ammonia: A parabolic flight experiment" — earliest publication
- Acevedo, Poventud-Estrada & Cabrera, Microgravity Sci Technol (2017): "Chronoamperometric Study of Ammonia Oxidation in a Direct Ammonia Alkaline Fuel Cell under the Influence of Microgravity"
- npj Microgravity (2023): AELISS ISS flight results — the key downstream publication (DOI: 10.1038/s41526-023-00265-4)
- NTRS citation (linked in TechPort): "Removal of Carbon Dioxide from Gas Mixtures Using Ion-Exchanged Silicoaluminophosphates" (related ECLSS work)
- Omoogun, Chatterjee, Ahmed & Cabrera, IntechOpen (Jan 2025): "Sequential Electrodeposition of Platinum-Nickel on Boron Doped Diamond Electrode for Ammonia Oxidation Reaction" — continues catalyst optimization work, exploring Pt-Ni bimetallic catalysts on BDD electrodes to improve AOR kinetics (link)
- Cabrera et al., ECS Advances (2024): Platinum-cerium oxide electrodeposition for fuel cell catalysis — continues core fuel cell catalyst development at UTEP
- Cabrera et al., IntechOpen (2026, forthcoming): Rotating disc slurry electrodeposition technique for nanoparticle synthesis — catalyst fabrication methodology
PI Career Trajectory¶
Carlos Cabrera moved from UPR-Río Piedras to the University of Texas at El Paso (UTEP) where he serves as Professor and Chair of Chemistry & Biochemistry. His research has diversified significantly since the AELISS work — active projects now span environmental remediation (uranium electrodeposition), biosensors (graphene-based immunosensor for colorectal cancer, ACS Omega 2025), and fundamental catalysis. Fuel cell catalyst work continues (Pt-CeO₂ electrodeposition, ECS Advances 2024) but no new NASA microgravity funding is visible.
Funding status (Session 75 update): - NSF-PREM "Center for Interfacial Electrochemistry of Energy Materials" ($4.2M, PI) — ended September 2024 - NSF Mid-scale RI-2 ($1M subaward, Co-PI) — runs through December 2025 - DOE SPINS ($1M subaward, Co-PI) — runs through September 2025 - No active NASA grants identified as of April 2026
Assessment: The ammonia/microgravity research line appears to have concluded with the AELISS ISS flight and 2023 publication. Cabrera's group is no longer actively pursuing space applications — the research has returned to terrestrial electrochemistry. This is a natural conclusion for a successful FO→ISS pipeline: the fundamental science question (how does microgravity affect AOR?) was answered.
ECLSS Context¶
The technology addresses a real gap in NASA's Environmental Control and Life Support System (ECLSS), which currently achieves ~90% water reclamation efficiency. Ammonia is a primary contaminant in urine processing. Converting ammonia to nitrogen + energy while producing clean water would improve reclamation efficiency for long-duration missions (Artemis, Mars transit). Cabrera's group also collaborated with Faraday Technology on a continuous bio-electrochemical reactor for urea removal.
Timeline¶
| Year | Event |
|---|---|
| 2012 | First publication: ammonia oxidation in parabolic flight (Acta) |
| 2013 | FO project [91638] begins; "Advanced To" outcome recorded |
| 2016 | FO project completes (TRL 6→7) |
| 2017 | Microgravity Sci Technol publication |
| 2020 | AELISS launched to ISS on NG-14 (October 1, 2020) — autonomous ammonia oxidation experiments in 2U NanoRacks module |
| ~2020 | Cabrera moves from UPR to UTEP |
| 2023 | npj Microgravity: AELISS ISS flight results published |
| 2024 | ECS Advances: Pt-CeO₂ fuel cell catalyst paper (UTEP) |
| 2025 | IntechOpen: Pt-Ni/BDD catalyst chapter; NSF-PREM $4.2M grant ends; ACS Omega biosensor + uranium papers |
| 2026 | IntechOpen: rotating disc slurry electrodeposition (forthcoming); no active NASA funding visible |
Maturation time: FO flight (2013) → ISS flight (2020) = 7 years; ISS flight → publication (2023) = 3 years
Research arc: Active space electrochemistry (2012–2023) → diversified to terrestrial applications (2024–present)
Verification¶
- Sample size: 2 FO projects (predecessor + 91638), "Advanced To" outcome, 7 publications, AELISS ISS flight confirmed
- Query used:
techport_get_project(91638), web search for Cabrera ammonia fuel cell NASA microgravity, PMC full-text read of npj Microgravity 2023, UTEP faculty profile review (Session 75) - Counter-query (Session 55 — resolved): AELISS ISS flight confirmed — launched on NG-14 (Oct 1, 2020), operated in 2U NanoRacks module, results published in npj Microgravity 2023
- Counter-query (Session 75): Is Cabrera still pursuing microgravity research? No — no active NASA grants, recent publications are terrestrial electrochemistry (uranium, biosensors, environmental remediation). The space research line has concluded.
- Confidence: Confirmed for FO → ISS flight pipeline and publications. This is a genuine FO → ISS mission infusion case. Research arc is complete — successful conclusion, not abandonment.
Cross-References¶
- Related ECLSS technology: Paragon COSMIC (condensate separator for ISS WPA)
- Related fuel cell: Teledyne Energy HEPS (hydrogen fuel cell for Artemis)
- Related fuel cell: Giner NFTFC (NASA SBIR Phase III RFC)
- Related fuel cell: [UPR DAAFC in tracker — 91638] — this is the canonical page
- Archetype: Academic FO → ISS Flight — FO parabolic flights generated fundamental science that was translated into ISS hardware over a 7-year arc. Similar pattern to NJIT EHD and RPI RSD. Upgraded from "ISS-Qualified Prototype" to "ISS Flight" in Session 55.
Updated: Session 75, 2026-04-07