About the Technological Readiness of the H₂ Generation by Hydrolysis of B(−N)−H Compounds

At the beginning of the new millennium, hydrolysis of sodium borohydride (NaBH 4 ) was presented as a promising on‐board technology to generate H 2 for light‐duty vehicles. Years later, other B(−N)−H compounds (e.g., lithium borohydride (LiBH 4 ) and ammonia borane (NH 3 BH 3 )) emerged as attractive alternatives whereas NaBH 4 was struggling with several issues jeopardizing its implementation. Actually, efforts in the research and development of H 2 generation by hydrolysis of B(−N)−H compounds have been intensive since the advent of NaBH 4 almost 20 years ago. There may be a question with respect to this: What is the technological readiness of the promising hydrolytic B(−N)−H compounds? This Review aims at providing relevant elements in response to this question. In the first part, the most mature B(−N)−H compounds are discussed at length. In the second part, a survey of all other candidates is proposed. It is concluded that NaBH 4 is the best hydrolytic B(−N)−H compound for marketing on a broad scale, but there are still key challenges to address.