Can burning hydrogen be used to generate electricity?

YES!!! Because, on burning, it releases heat energy, which can generate steam to drive steam turbines and thereby rotate dynamos to make electricity.

However, the energy balance is NOT in favour of this process, because making hydrogen gas requires more energy than burning hydrogen releases energy.

Also there is a lot of research on hydrogen cells using water hydrogen oxygen and transfer of electrons to form electricity.

Anything that gives off heat can be used, it's the harnessing of it that might prove difficult.

Yes, you can combine hydrogen with oxygen to create water and energy.

yes, as can burning natural gas or any other petroleum product.

a power plant burning natural gas can be easily converted to burning hydrogen if needed.

But there is no source of hydrogen that doesn't use large amounts of energy to produce it.