Fossil fuels as the current major energy source has promoted many environmental issues due to the large-scale emission of CO2 and other pollutants. Issues brought by fossil fuels include global warming, climate change, and sea level rise. Solar energy as a clean energy source has caught great interest globally, and is belived to be a promising solution to climate change and fossil fuel depletion. Photoelectrochemical water splitting (PEC) is an effective solar conversion technology to store the energy in hydrogen gas (H2).

There are four main preparation methods of preparing tungsten copper: mixed-press sintering method, activation sintering method, infiltration method, and nano/ultrafine mixed powder sintering method.

Nitrogen oxides (NOx) are produced from the emissions of stationary sources and automobiles. Direct emission of NOx into the atmosphere without purification will lead to photochemical smog, acid rain and even global warming. The selective catalytic reduction (SCR) of NO with NH3 is widely employed for reduction of NOx emissions from stationary sources like gas, oil and coal- fired power plants. The most common catalyst is vanadium well-dispersed on a titania support as V2O5-TiO2.

Glycerol is a byproduct of overcapacity from biodiesel manufacture. Selective hydrogenolysis of glycerol to 1,3-propanediol (1,3-PDO) has seen an increasing industrial demand as the glycerol derived from biodiesel production. By the way, 1,3-PDO has been largely utilized in solvents, cosmetics, cleaning products, pharmaceutical industries, and organic synthesis intermediates.