When people think of hydrogen energy, they picture clean cars, not underground rock layers. But for Abduljeleel Ajibona, a Nigerian PhD researcher, the future of clean energy depends on what lies beneath. From quarry work in Nigeria to labs in the U.S., he’s leading vital research on underground hydrogen storage and why shale caprocks may hold the key to a safer, greener energy transition.

Let’s start from the surface  when most people hear about hydrogen energy, they picture fuel cells or clean vehicles. But your work focuses on what happens beneath the ground. Why is that equally important?

It is easy to get excited about the cars and gadgets powered by hydrogen, but few people stop to ask: Where will all that hydrogen come from, and how will we store it safely? One of the most promising ways to do that is by storing large amount of hydrogen deep underground, in spaces like old gas reservoirs. My research evaluateshow well the overlying rock called caprock can seal in hydrogen and prevent it from leaking. We simulate storage conditions in the lab to understand how these rocks respond over time. This is a critical part of building a safe, reliable hydrogen infrastructure because if storage isn’t secure, the whole system is at risk.

Your recent study on pycnometric evaluation of shale caprocks is making waves in the clean energy space. What big question were you trying to answer with this research?

The central question driving this research was: Can shale caprocks maintain their sealing integrity under the cyclic stresses of hydrogen injection and withdrawal?For underground hydrogen storage to be safe and viable, the overlying caprock must act as an effective seal to prevent leakage. My goal was to evaluate whether key properties, particularly porosity and permeability, change when shale is exposed to repeated hydrogen cycling. Using a pycnometric approach, I assessed these changes at a microstructural level to better understand if prolonged hydrogen exposure could compromise the caprock’s ability to contain gas securely. This is a critical step in determining the long-term reliability of geological formations for clean energy storage.

Shale caprocks aren’t exactly common dinner-table conversation. For those new to the topic, why are they so central to the future of underground hydrogen storage?

Shale caprocks are one of the most important factors in making underground hydrogen storage safe and practical. These rock layers sit above storage reservoirs and act as natural seals. What makes shale so valuable is its extremely low porosity and permeability, which prevents stored gases or fluids from easily passing through. That is especially important for hydrogen, which is a very small and mobile molecule. If we want to store hydrogen underground at large scale in a safe and economically viable manner, without costly leakage, we need caprocks that can reliably hold it in place. Shale has the right properties to do that, making it central to the future of secure, long-term hydrogen storage.

One of the standout aspects of your work is the use of pycnometry. How does this technique work, and why is it uniquely suited to evaluating underground storage safety?

Pycnometry is a technique used to determine the volume present in the rock. In the context of underground hydrogen storage (UHS), this is particularly important. Hydrogen is the smallest and most diffusive molecule, and even micro- or nanopores in shale caprock can pose leakage risks. By using pycnometry, we can quantify how pore structure evolves under cyclic hydrogen injection and depletion. This helps us assess whether the caprock maintains its sealing integrity or becomes more susceptible to leakage over time. In short, pycnometry gives us a direct window into how safe and reliable a rock formation is for long-term hydrogen containment.

Many governments are investing in hydrogen infrastructure, but conversations about subsurface safety often take a backseat. From your perspective, what’s missing from the global conversation?

There’s a strong global push toward hydrogen as a clean energy carrier, which is encouraging, but most of the attention is on production, transport, and end-use technologies. What’s often overlooked is where and how we store hydrogen at scale. Subsurface storage, especially in depleted reservoirs and salt caverns, is critical for energy security and supply stability. Yet, we still lack a deep understanding of how hydrogen interacts with the rocks and seals that are meant to contain it.

From my perspective, what’s missing is a dedicated focus on long-term containment performance, how rocks like shale caprocks respond to hydrogen exposure over time, especially under cycling conditions. Without this knowledge, we risk running into leakage, loss of gas, or even broader environmental concerns. It’s not just a technical detail, it’s a foundational issue. For hydrogen to fulfill its promise as a large-scale energy solution, subsurface integrity needs to be part of every national hydrogen strategy.

Let’s talk Africa. Do you see potential for underground hydrogen storage across the continent, and what needs to happen for countries like Nigeria to play a leading role?

Yes, there is real potential for underground hydrogen storage in Africa, and especially in resource-rich countries like Nigeria. Many African nations already have subsurface infrastructure from oil and gas operations, including depleted reservoirs, geological data, and technical expertise which could be repurposed for hydrogen storage. Nigeria, in particular, has extensive sedimentary basins with favorable geological formations, including shales and sandstones that could be suitable for safe, long-term storage.

But to turn this potential into reality, a few key steps are needed. First, we need targeted research and site characterization to understand which formations are technically viable for hydrogen storage. Second, investment in local capacity-building; from laboratory infrastructure to training programs will be critical. And third, clear regulatory frameworks must be developed to ensure safe and responsible deployment.

If countries like Nigeria can align their energy transition goals with investments in underground storage, they could become not just hydrogen producers, but also regional leaders in hydrogen infrastructure. That would position Africa as an active player in the global clean energy economy, rather than a bystander.

You’ve worked in both industry and academia, from quarry sites in Nigeria to research labs in the U.S. How has this shaped your approach to problem-solving in energy science?

Having worked across both industry and academia; from quarry sites in Nigeria to research laboratories in the United States, my approach to problem-solving in energy science is shaped by both hands-on experience and scientific rigor.

In Nigeria, I served as a mining engineer in a granite quarry, where I was responsible for mine planning, drilling and blasting coordination, and overseeing daily production activities. These responsibilities demanded practical, on-the-spot decision-making and resourcefulness, especially in environments where efficiency, safety, and adaptability were critical to success. It gave me a foundational understanding of how energy and resource systems operate at ground level, and how engineering decisions directly impact productivity and people.

Transitioning into academia, particularly in the U.S., I’ve had the opportunity to explore the science behind these systems; investigating the behavior of caprock formations, modeling subsurface hydrogen storage, and conducting laboratory-based geomechanical testing. This environment taught me to approach challenges systematically, using data and experimentation to develop scalable and forward-looking solutions.

Bringing these two worlds together, I now approach energy science with a perspective that values both immediate practicality and long-term sustainability. I aim to develop solutions that not only withstand academic scrutiny but also deliver tangible value in the field, especially as we transition to cleaner and more secure energy systems.

Your journey began at the Federal University of Technology Akure. Looking back, what parts of your Nigerian education and early career have proven most valuable in your PhD research today?

My education at the Federal University of Technology Akure (FUTA) laid the groundwork for everything I do today. The curriculum was rigorous and broad, covering both theoretical and applied aspects of mining engineering. Courses like Mine Planning, Rock Mechanics, and Drilling and Blasting gave me a solid technical foundation, but what stood out most was the emphasis on resourcefulness and adaptability, skills that are essential in both fieldwork and research.

Equally valuable was my early industry experience in Nigeria, where I worked as a mining engineer in a granite quarry. There, I learned how to navigate real-world engineering problems; how to make quick, informed decisions, manage people, and stay focused under operational constraints. That experience taught me to think beyond textbooks and consider the practical impact of engineering decisions.

These early experiences continue to shape my PhD research, especially as I work on complex subsurface energy problems like underground hydrogen storage. Whether I’m designing lab experiments or analyzing rock behavior under stress, I bring with me not just technical knowledge, but also a mindset shaped by hands-on problem-solving, discipline, and a deep appreciation for applied engineering.

As a PhD candidate focused on clean energy, what’s one myth about hydrogen storage you often find yourself correcting? 

One common myth I often encounter is the idea that hydrogen, once injected underground, will simply stay there without issue, just like natural gas. In reality, hydrogen behaves very differently. It’s the smallest and most mobile molecule, which means it can diffuse through even the tiniest pores or imperfections in the surrounding rock. It can also interact with minerals, microbes, and water in ways that might compromise storage integrity over time.

My research focuses specifically on evaluating shale caprocks, the geological seals that are meant to trap hydrogen in place. We test how these rocks respond to repeated hydrogen injection and withdrawal cycles, to understand whether their sealing capacity holds up in real-world conditions. So the myth isn’t just about storage being “easy”, it’s about underestimating the complexity of the subsurface environment and the rigorous science needed to ensure long-term safety and reliability.

Your work intersects with climate action, sustainable development, and energy equity. In what ways does your research contribute to broader global goals like the UN SDGs?

My research contributes directly to several of the United Nations Sustainable Development Goals, especially SDG 7 (Affordable and Clean Energy), SDG 13 (Climate Action), and SDG 9 (Industry, Innovation, and Infrastructure). By focusing on underground hydrogen storage, I am addressing one of the major challenges in the clean energy transition: how to store large volumes of renewable energy safely and efficiently. Hydrogen is a critical enabler of decarbonization across hard-to-abate sectors, and developing reliable storage systems is essential for making it a scalable solution. My work helps ensure that these systems are not only technically feasible, but also geologically secure, preventing leaks, reducing environmental risk, and supporting long-term deployment.

Beyond technical innovation, this research also supports energy equity. Countries like Nigeria and others across the Global South have extensive subsurface resources and existing oil and gas infrastructure that could be repurposed for hydrogen storage. By generating scientific knowledge that can be applied globally, my work aims to help these countries participate in- and benefit from the growing hydrogen economy, fostering inclusive and sustainable development. Ultimately, I see my research as a bridge between science and policy, supporting a cleaner, safer, and more equitable energy future.

What are some of the international platforms or forums where your research is gaining recognition and how does that visibility help shift narratives around African-led innovation?

My research on hydrogen storage in depleted gas reservoirs is beginning to gain recognition within the global clean energy and geoscience communities. It has attracted interest through reputable hydrogen storage journals through citations, academic platforms like ResearchGate, and professional networks such as LinkedIn, where peers and experts have engaged with and recommended my work.

As one of the few African-led studies in this emerging area, this visibility is especially meaningful. It not only highlights the potential of African researchers to contribute to high-impact global challenges but also helps shift the narrative that innovation from Africa can be at the forefront of cutting-edge energy solutions. I hope this encourages more researchers across the continent to explore complex subsurface technologies and to see themselves as active contributors to the global energy transition.

Scientific research can be lonely and complex. What keeps you grounded and motivated, especially when working on highly technical, long-term projects?

What keeps me grounded is the deep sense of purpose that brought me into this field in the first placewhich is my passion for environmental sustainability. From the moment I chose to study mining engineering, I knew I wanted to make a positive impact, not just by extracting resources more responsibly, but by contributing to solutions that address our global climate challenges.

My work in underground hydrogen storage is a natural extension of that commitment. It allows me to be part of a larger movement toward reducing carbon emissions and transitioning to cleaner energy systems. Even during difficult or isolating moments in research, I remind myself that the work I am doing contributes to something far greater than myself, a more sustainable and secure future for communities and the planet.

That vision is what drives me forward. It gives meaning to the long hours and technical challenges and keeps me focused on the impact I hope to make.

What are the next steps for your research? Any upcoming collaborations, field studies, or new directions we should watch out for?

One of the key limitations in my earlier work using pycnometry was that it relied on crushed rock grains to assess porosity and permeability changes, an approach that does not fully capture the complexity of field conditions. To address this, I recently advanced the methodology by using intact shale chunks, offering a more realistic representation of subsurface behavior during hydrogen exposure. The findings from that work are currently under review for publication.

Looking ahead, I plan to scale up further by using full rock cores to assess geomechanical and petrophysical changes under cyclic hydrogen injection and depletion. I’m also working on integrating these experimental results into reservoir simulators, such as Computer Modelling Group (CMG)software, to better simulate and predict field-scale performance.

In parallel, I am actively collaborating with other research groups and industry partners to explore the role of microbial activity in hydrogen storage systems, both in laboratory and field settings. This multidisciplinary approach, combining geomechanics, microbiology, and reservoir engineering will be central to my future work, as we seek to ensure safe, scalable, and sustainable underground hydrogen storage.

Finally, what message would you share with young African scientists and engineers who want to tackle global energy problems but may not know where to start?

First and foremost, cultivate a genuine passion for solving environmental and energy challenges—because that passion is what will keep you going when resources are scarce or the path seems unclear. The energy transition is a global challenge, and Africa has a vital role to play. Your ideas, perspective, and local understanding matter.

Don’t underestimate the power of mentorship. Surround yourself with people, such as professors, industry professionals, researchers, who have walked the path and can guide you through the complexities of science, engineering, and career development. Ask questions, stay curious, and stay connected.

Start by collaborating with your peers, sharing ideas, learning new tools, and working on real-world problems together. Then expand your network to include mentors and professionals in your field. Opportunities often emerge through collaboration and visibility, not just through formal applications.

Finally, believe that your work can have global relevance. You do not have to wait for perfect conditions to start. You can begin where you are, with what you have, and grow from there. Africa needs more scientists and engineers who are not only brilliant, but bold. So step forward, stay committed, and know that your contribution can help shape the future of energy, not just for the continent, but for the world at large.

Conclusively, Ajibona’s work goes beyond science, it bridges continents, disciplines, and energy futures. By spotlighting underground storage as a missing link in global clean energy plans, he’s advancing climate solutions and positioning African expertise at the center of the conversation.