A system for distribution of hydrogen gas in a metal hydride reactor is disclosed. The system comprises a hydrogen distribution conduit positioned within a metal tube so as to define an annular space between the hydrogen distribution conduit and the outer metal tube. The hydrogen distribution conduit provides a flow passage for the hydrogen gas. A metal sponge matrix containing hydrogen-storing metal powder or hydrogen-storing alloy powder is filled in the annular space. The system provides a more uniform distribution of hydrogen across the particles of the hydrogen-storing metal/alloy powder, provides mechanical support to the hydrogen distribution conduit, improves the thermal conductivity of the powdered metal/alloy bed and reduces the size and production cost of the reactor.