The Enzyme Molecules That Speed Up Biochemical Reactions

As all the living organisms depending on the enzyme molecules; that speed up biochemical reactions that are essential for life. The study trying to create artificial enzymes capable of cranking out important chemicals; and fuels at an industrial scale with performance rivaling their natural counterparts. Developing a synthetic catalyst that produces chemicals much the way enzymes do in living organisms.

Effective catalysts stabilize specific transition states and control the transport of species to and from catalytically active sites. But enzymes showing these traits thanks to their diverse amino acid functional groups encapsulating metal centres; but are limited in the reaction conditions in which they can operate. Methanol has a variety of applications; and there is a growing demand for its use as a fuel with lower emissions than conventional gasoline.

The biochemical reactions

As the researchers designing a catalyst made of nanocrystals of palladium; a precious metal, embedded in layers of porous polymers tailored with special catalytic properties. Most protein enzymes found in nature also have trace metals, like zinc and iron, embedded in their core; by observing trace palladium in their catalysts with electron microscopic imagery. Realizing a catalyst with this kinetic and transport control that can be used under demanding industrial conditions is challenging.

But the catalyst in a reactor tube with a continuous flow of carbon monoxide and oxygen gas. When the tube was heating to about 150 degrees Celsius (302 degrees Fahrenheit); the catalyst began generating the desired product, carbon dioxide. High-energy X-rays from the Stanford Synchrotron Radiation Lightsource (SSRL) at SLAC revealing; that the catalyst had traits similar to those seen in enzymes.

Enzymatic activities

The palladium nanocrystals inside the catalyst were continuously reacting with oxygen and carbon monoxide to produce carbon dioxide. And some of the newly forming carbon dioxide molecules were getting trapping in the outer polymer layers as they escaped from the nanocrystals. This is important, because it’s the same strategy used by enzymes. When an enzyme produces too much of a product, it stops working, because the product is no longer needing.

An artificial catalyst that directly converts methane to methanol would require much lower temperatures and emit far less carbon dioxide; But the demonstrating that can prepare hybrid materials made of polymers and metallic nanocrystals that have certain traits typical of enzymatic activity.  The polymer chemistry and morphology control the catalytic performance of the metal sites, affecting the transition state for CO oxidation and controlling the transport of CO2 away from the active site.