Biofuel Cells With Enzymes as a Catalyst

A biofuel is made directly through biological procedures, rather than a fuel made by geological procedures, which are related to the formation of fossil fuels on the basis of prehistoric biological matter (e.g., coal and petroleum). For alleviating the usage of fossil fuels and CO₂ emissions, heat, fuels, and electricity must be made from biological sources. A fuel cell, as the favorable currently emerging technology, uses chemical energy from fuel to make electricity and satisfies the demand for clean, green, effective, and renewable processes. To date, to reduce oxygen in most traditional fuel cells, platinum-based catalysts have been used. Notwithstanding, optimistic results show that platinum-based catalysts have a number of challenges in large-scale commercial products, where the primary issue is the high cost of platinum-based catalysts and the passivation of the electrode, because of fuel crossover to the cathode and the large overpotential. 
To overcome these issues, new techniques are being explored by using bioelectrocatalytic enzymes to replace platinum-based catalysts. Adopting enzymes as catalysts on the cathode has the following benefits: (1) enzymes are extremely selective, (2) they show higher catalytic activity than platinum-based catalysts, (3) they are biodegradable, green, nontoxic, clean, and do not interfere with living body cells, and (4) they are cheaper than most platinum-based catalysts. 
Therefore biofuel cells with enzymes as catalysts reveal crucial information about biofuels as clean, green, and renewable energy with an environmentally friendly nature.