Bigger Picture: The Hydrogen Catalyst: Removing a Quantum Barrier to Fuel Sustainable Aviation

Speaker: Paula Mendoza-Moreno, Dept of Chemical Engineering and Biotechnology, University of Cambridge

Abstract

The single greatest barrier to hydrogen (H₂) aviation is the immense challenge of storing and distributing liquid hydrogen (LH₂). This challenge is the primary obstacle to making flights that emit only water a practical reality. A significant part of this challenge stems from a fundamental property of H₂ itself: the interconversion of its isomers, ortho- and para-H₂, under liquid storage conditions. This exothermic isomerisation reaction is a major, direct contributor to the quick evaporation of LH₂, making fuel storage inherently inefficient. A solution is to promote the ortho-para conversion (OPC) with a catalyst in liquefaction. This enables the supply of stable LH₂ fuel that meets the standards required by H₂ aircraft designs.

This lecture will present findings from a recent study demonstrating that the industry-standard pursuit of >99% para-hydrogen purity is not only more expensive than we thought but also energetically sub-optimal for the aviation fuel cycle. The findings reveal that a strategically-tuned OPC process, accepting purities of 83-95%, reduces liquefaction energy demands by 8-13% while reducing evaporation losses during storage for the critical 1-7 day transport window. This optimisation, when coupled with green H₂ production, leads to a >92% reduction of CO₂ emissions from fuel production to flight on routes such as London-New York. Furthermore, this talk will outline the experimental continuation of this work, building on the kinetic understanding of the catalytic OPC. The new insights gained into this quantum phenomenon directly address the evaporation of H₂ in storage tanks, the economic viability of H₂ aviation, and the carbon footprint of the LH₂ supply.

Part of the Bigger Picture Talk Series 

Speaker Bio:

Paula Mendoza-Moreno is a Gates Cambridge Scholar and a final year PhD Candidate in Chemical Engineering at the University of Cambridge. Her research focuses on overcoming core engineering challenges in liquid hydrogen storage and distribution to enable its adoption as a sustainable aviation fuel.

By bridging theoretical chemistry, quantum mechanical principles, and practical process design, she aims to develop scalable and efficient LH₂ infrastructure solutions. Her current work centres on the ortho- to para-hydrogen conversion kinetics and the environmental sustainability of hydrogen aviation systems. Paula holds a bachelor’s degree in chemical and biological engineering from Colorado State University.

She has worked on techno-economic and life cycle assessment projects for advanced biofuels at Argonne National Laboratory, high-value commercialisation pathways of natural resins with the U.S. Department of Agriculture, and sustainable bio-economies for arid regions at the Colorado State University Energy Institute.