How does hydrogen based cars work?

Hydrogen based cars use hydrogen as the fuel and are pollution free. The basic idea was to reduce consumption of crude oil extracts as fuel and reduce pollution levels due to environmental concerns. Hydrogen based cars can have two types of constructions – one which converts chemical energy of hydrogen to mechanical energy either by burning hydrogen in the internal combustion engine, or by reacting hydrogen with oxygen in a fuel cell in a controlled manner to run electric motors . Use of hydrogen will greatly reduce CO2 emissions, and result in reduction of green house gases’ emission of a vehicle.