Metallic conductivity and high temperature superconductivity are predicted to manifest in solid hydrogen at sufficiently high pressures. However, experimental limitations resulting from the combination of GPa pressures and microscopic sample sizes have prevented robust and reproducible experimental measurements on the properties of these solid hydrogen phases. 

Molecular confinement in optimally sized nanopores can dramatically affect the phase diagram of pure substances, resulting in anomalous phase behavior. Accordingly, we confined hydrogen in a range of nanoporous solids and used a combination of neutron scattering techniques under low temperatures (down to 10 K) and high pressures (up to 2 kbar) to elucidate the phase, interactions and behaviours of hydrogen inside porous materials with different pore sizes and geometries.

These results indicated the presence of molecular hydrogen arrangements with densities greater than that of solid hydrogen at its triple point, as well as the stabilisation of unusual configurations of hydrogen under a variety of temperature and pressure conditions. Moreover, we measured the magnetic and electrical properties of the dense hydrogen phase in-situ and demonstrated that the confined dense hydrogen switches to a paramagnetic state with a reduction in resistivity with increasing high density H2 content. These results indicate that hydrogen densification by confinement could present a route to the formation of metallic hydrogen at significantly lower, more experimentally accessible pressures, and hints at the possibility of using hydrogen for storage of electrical as well as chemical energy.

Professor Valeska Ting (CEng, FIOM3, MRSC) is a materials scientist and an engineer, working in the field of sustainable technologies. She completed her PhD in Chemistry at ANU in 2007, before moving to the UK to take up a postdoctoral research position at the University of Southampton and a Research Fellowship and lectureship at the University of Bath in Chemical Engineering, becoming a Chartered Chemical Engineer and a Fellow of the Higher Education Academy in the process. She joined the University of Bristol in 2016, where she was awarded a highly competitive research fellowship from the UK’s Engineering and Physical Sciences Research Council and was promoted to Professor of Smart Nanomaterials in the Department of Mechanical Engineering in 2019. 

Valeska moved to the ANU in late 2022 to take up a joint position as a Professor in the Research School of Chemistry, as well as the Associate Dean of Research, Engagement and Impact for the College of Engineering, Computing and Cybernetics. She heads a team of researchers working on the design, characterisation and testing of materials for sustainable energy applications. Her research has been recognised by the award of the 2013 Institution of Chemical Engineers’ Sir Frederick Warner medal, as well as the UK's Parliamentary and Scientific Committee's SET for Britain Gold Medal for Engineering and the Westminster Medal in 2013. In 2020 she was named in the Top 50 Women in Engineering working in sustainability.

^{[1] Ting, V. P, Ramirez-Cuesta, A. J., Bimbo, N., Sharpe, J. E., Noguera Diaz, A., Presser, V., Rudic, S. and Mays, T. J., 2015. Direct evidence for solid-like hydrogen in a nanoporous
carbon hydrogen storage material at supercritical temperatures. ACS Nano, 9 (8), 8249–8254}

^{[2] Tian, M., Lennox, M.J., O’Malley, A.J., Porter, A.J., Krüner, B., Rudić, S., Mays, T.J., Düren, T., Presser, V., Terry, L.R. Ting V.P., 2020. Effect of pore geometry on ultra-densified hydrogen in microporous carbons. Carbon 173, pp 968–979}