5 Hydrogen Fuel Cell Opportunities

Question 1

Why is hydrogen used in fuel cells (3)

Answer 1

High energy density
Only byproduct is water
More efficient than internal combustion engines and electricity generators

Question 2

How is hydrogen extracted 3 different ways

Answer 2

Steam reforming of fossil gases
Electrolysis of water
Photocatalytic water splitting

Question 3

Name 5 common forms of hydrogen fuel cells

Answer 3

Polymer electrolyte membrane PEM
Alkaline
Phosphoric acid
Molten carbonate
Solid oxide

Question 4

Describe the process of energy conversion in PEM hydrogen fuel cell

Answer 4

H2 is reduced at anode after passing through its selectively permeable membrane forming H+ and e-
e- flow through circuit powering a motor
Ions pass through electrolyte to cathode where e- H+ and O2 react forming H2O and heat

Question 5

Oxidation reaction at anode hydrogen fuel cell

Answer 5

H2 -> 2H+ + 2e-

Question 6

Reduction Reaction at cathode hydrogen fuel cell

Answer 6

4H+ + 4e- + O2 -> 2H2O

Question 7

Range of applications of hydrogen fuel cells (3)

Answer 7

Stationary generation as backup or in remote locations
Stand alone power supply for telecommunications installations
Transport / power generators

Question 8

Discuss the challenges presented by using hydrogen as an energy source (3)

Answer 8

Expensive to produce because of electricity required. More expensive per unit than petrol
Specific infrastructure needed such as special filling stations
Storage and transport are complicated due to the fact it is flammable and is stored as a liquid