Instead of reacting together on the surface of the catalyst (the palladium cluster), the hydrogen
atoms dissociate into their components--protons and electrons. The protons enter the
surrounding solution of water and methanol, while the electrons flow through the palladium
itself into oxygen molecules. Credit: American Chemical Society.
(January 20, 2016) From the polyurethane that makes our car seats to the paper made from bleached wood pulp, chlorine can be found in a variety of large-scale manufacturing processes. But while chlorine is good at activating the strong bonds of molecules, which allows manufacturers to synthesize the products we use on a daily basis, it can be an insidious chemical, sometimes escaping into the environment as hazardous byproducts such as chloroform and dioxin.
As a result, scientists and companies have been exploring a more environmentally benign alternative to chlorine—hydrogen peroxide, or H2O2. But it is an expensive reactant. Hydrogen peroxide is typically made in big, centralized facilities and requires significant energy for separation, concentration, and transportation. A handful of large-scale facilities around the globe have begun to produce H2O2 using the current process, but at the same facilities as the polyurethane precursors, which results in significant cost and energy savings and reduces environmental impact. Ideally smaller-scale factories would also be able to make hydrogen peroxide on site, but this would require a completely different set of chemistry, direct synthesis of H2O2 from hydrogen and oxygen gas, which has long been poorly understood according to University of Illinois researchers.