Toyota (in collaboration with Yamaha) is developing a V8 hydrogen combustion engine [1]. BMW also developed a V12 hydrogen combustion engine back in 2005 [2].

"Engineering Explained" has put out videos on both, and neither of them sound very appealing to me. [3][4]

[1] https://www.topgear.com/car-news/future-tech/toyota-and-yama...

[2] https://en.wikipedia.org/wiki/BMW_Hydrogen_7

[3] https://www.youtube.com/watch?v=vJjKwSF9gT8

[4] https://www.youtube.com/watch?v=AouW9_jyZck