Citation: Yusnizam, N.Y.; Ali, N.A.; Sazelee, N.; Ismail, M. Boosting the Dehydrogenation Properties of LiAlH 4 by Addition of TiSiO 4 . Materials 2023, 16, 2178. https://doi.org/10.3390/ ma16062178 Academic Editors: Alessandro Dell’Era and Erwin Ciro Zuleta Received: 7 February 2023 Revised: 21 February 2023 Accepted: 23 February 2023 Published: 8 March 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). materials Article Boosting the Dehydrogenation Properties of LiAlH 4 by Addition of TiSiO 4 Nurul Yasmeen Yusnizam, Nurul Amirah Ali , Noratiqah Sazelee and Mohammad Ismail * Energy Storage Research Group, Faculty of Ocean Engineering Technology and Informatics, Universiti Malaysia Terengganu, Kuala Nerus 21030, Malaysia; nurulyasmeen.yusnizam@gmail.com (N.Y.Y.); nurulllamirah@gmail.com (N.A.A.); atiqahsazelee19@gmail.com (N.S.) * Correspondence: mohammadismail@umt.edu.my; Tel.: +60-9-6683487 Abstract: Given its significant gravimetric hydrogen capacity advantage, lithium alanate (LiAlH 4 ) is regarded as a suitable material for solid-state hydrogen storage. Nevertheless, its outrageous decomposition temperature and slow sorption kinetics hinder its application as a solid-state hydrogen storage material. This research’s objective is to investigate how the addition of titanium silicate (TiSiO 4 ) altered the dehydrogenation behavior of LiAlH 4 . The LiAlH 4 –10 wt% TiSiO 4 composite dehydrogenation temperatures were lowered to 92 ◦ C (first-step reaction) and 128 ◦ C (second-step reaction). According to dehydrogenation kinetic analysis, the TiSiO 4 -added LiAlH 4 composite was able to liberate more hydrogen (about 6.0 wt%) than the undoped LiAlH 4 composite (less than 1.0 wt%) at 90 ◦ C for 2 h. After the addition of TiSiO 4 , the activation energies for hydrogen to liberate from LiAlH 4 were lowered. Based on the Kissinger equation, the activation energies for hydrogen liberation for the two-step dehydrogenation of post-milled LiAlH 4 were 103 and 115 kJ/mol, respectively. After milling LiAlH 4 with 10 wt% TiSiO 4 , the activation energies were reduced to 68 and 77 kJ/mol, respectively. Additionally, the scanning electron microscopy images demonstrated that the LiAlH 4 particles shrank and barely aggregated when 10 wt% of TiSiO 4 was added. According to the X- ray diffraction results, TiSiO 4 had a significant effect by lowering the decomposition temperature and increasing the rate of dehydrogenation of LiAlH 4 via the new active species of AlTi and Si-containing that formed during the heating process. Keywords: LiAlH 4 ; TiSiO 4 ; hydrogen storage; dehydrogenation properties 1. Introduction Concerns about the energy crisis and the environment have led to an increase in the proportion of renewable energy sources in the energy system, such as wind, hydro, and other types. The supply and utilization times are typically out of sync and have some geographical restrictions. The proper secondary energy must be selected to match them, and hydrogen is a promising alternative to meet the demands for clean and sustainable energy technologies [1]. Hydrogen energy is a perfect substitute for petroleum because of its high energy density and lack of carbon emissions [2–7]. Hydrogen can be stored in a variety of ways for application purposes. As of now, compressed gas has been the most popular technique. It can also be kept as a liquid at extremely low temperatures. Other methods of storing hydrogen are via the solid-state method through physisorption and chemisorption [8]. Storing hydrogen via the solid-state method is regarded as the most promising method. Based on the US Department of Energy (DOE), by 2025, the fuel cell materials should store 5.5 wt% (gravimetric) and 40 g L -1 (vol- umetric) of hydrogen [9]. Complex hydride has emerged as the most promising medium for solid-state hydrogen storage based on the DOE target due to its high hydrogen storage capacity. Additionally, based on previous research, storing hydrogen is promising in metal or complex hydrides via chemisorption. This technique involves absorbing and storing Materials 2023, 16, 2178. https://doi.org/10.3390/ma16062178 https://www.mdpi.com/journal/materials