The first hydrogen train in the UK, Hydroflex, performed a 25-mile trip at a maximum speed of 50 mph. This is still a prototype, it will be ready to actually carry passengers in 2021.
Watch this video from BBC News if you want to know more about the project:
And to know more, please look at this website, Porterbrook is the company that is financing the development of the Hydroflex: https://www.porterbrook.co.uk/
The project is done in cooperation with the University of Birmigham Centre for Railway Reserearch and Eductaion (BCRRE): https://www.birmingham.ac.uk/research/spotlights/hydrogen-powered-train.aspx