Research Projects

Hydrogen is recognized as a clean and sustainable fuel for the transportation sector. However, its use is hindered by challenges in storage and transport due to low density and energy-intensive compression required. Ammonia has emerged as a promising liquid H2 carrier, offering 87.5 times lower storage pressure than H₂ and benefiting from an established global production and transport infrastructure. NH₃ can be transported over long distances and cracked into H₂ and N₂ at the point of use, making it one of the most industrially viable liquid H2 carriers. Despite this promise, the NH₃-H₂ energy pathway remains economically and technically limited for distributed applications in automotive and maritime sectors. Direct combustion of NH₃ in internal combustion engines is constrained by its low specific energy, slow laminar flame speed, and high ignition energy requirements. Consequently, cracking NH₃ into H₂ is essential for its use in vehicles. However, conventional NH₃ cracking relies on thermal catalysis at high temperatures (700–900 °C), requires expensive noble metal (Ru) catalysts and centralized reactors due to scale, cost and, complexity. The H2 produced from centralized crackers need to be purified and recompressed (above 700 bar) for storage in vehicles – with the energy-intensive compression step alone accounting for more than 25% of the levelized cost of hydrogen transport, thereby reducing overall energy and economic efficiency of the process. To overcome these challenges, we propose the development of an innovative low-temperature “photothermal” NH3 cracking technology that can facilitate onboard NH3 cracking with direct integration with mixed NH3-H2 IC engines. This modular low-temperature approach eliminates the need for centralized cracking and intermediate purification/compression steps, while opening opportunities for heat integration with engine exhaust and eliminating fossil-derived heat input for the endothermic cracking process. The core innovation lies in the design of effective photothermal catalysts, that synergistically harness light (LED/ full-spectrum/ UV) and heat to significantly lower NH3 cracking temperature to 300 – 450 oC, enabling compact reactor designs suitable for onboard applications. Our catalyst design will focus on non-noble metal-based systems, integrating Ni nanoparticles with plasmonic materials such as TiN, ZrN, or Cu in rationally engineered ‘core-shell/ yolk-shell’ nanostructures. These specialized catalyst architectures will be tailored to enhance light absorption, local heating, and interfacial interactions between active and plasmonic components. Building on our previous success in photothermal CO₂ hydrogenation using core-shell catalysts, we anticipate achieving temperature reductions of over 200 °C for NH₃ cracking, which would represent a breakthrough for onboard NH3 cracking. A unique feature of our approach is the integration and co-development of the NH₃ cracker with NH₃–H₂ engines, mapping reactor output with combustion characteristics, that will define performance targets, optimal process conditions, and accelerate technology readiness. A central focus will be on optimizing degree of NH₃ cracking – partial NH3 cracking is sufficient for NH₃–H₂ engines, but the extent of cracking critically impacts catalyst/reactor design, combustion efficiency, NOx emissions, and engine exhaust profiles. To determine optimal NH₃-H₂ fuel compositions, we will conduct combined experimental and simulation studies on engine performance across varying cracking levels, focusing on linear flame velocities, emissions, and energy efficiencies. We will also explore system-level integrations for engine exhaust heat recovery to drive the photothermal reaction. This interdisciplinary and holistic approach, combining catalysis, combustion, and energy science, is expected to transform the NH3 route of green H2 usage for automotive sector and is projected to reduce H2 transport costs by more than 30%.