Heterogeneous Catalysis
Catalysis is a part of chemistry familiar to many people inside, and outside, the world of science. Catalysts are used in many processes vital for our day to day lives, from food processing to waste disposal; even inside our bodies enzymes are functioning as catalysts in many of the reactions essential for our survival. This review will discuss some of the uses and impacts of catalytic research, particularly heterogeneous catalysis, the work of Gabor Somorjai and modern problems in heterogeneous catalysis.
The idea of catalysis was first put forward by the Scottish scientist Elizabeth Fulhume in 1794.1 A catalyst is a substance that will provide an alternative pathway for a reaction, increasing the rate of reaction,
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AES relies on the detection of electrons emitted from surface atoms when excited by X-Ray, electron or ion bombardment.4 In HREELS, low energy electrons interact with the surface of the analyte causing inelastic reflection of electrons. Inelastic reflection describes reflection of a particle from a surface where the energy of the incident particle is either lost or increased. Typically (though not necessarily) in HREELS, this is due to the absorption of energy by surface atoms causing vibrational excitation. The energy of the reflected particle can be measured and used to calculate the energy absorbed by the surface atoms.5 Therefore this technique gives information on bonding and structure of surfaces and adsorbed molecules.4
Gabor Somorjai and his team developed a new instrument using techniques such as AES and HREELS in combination with gas chromatography, to characterise catalyst surfaces as well as determining the kinetics of catalytic surface reactions.4
Lattices will give different surface structures depending on the angle that they’re cut at (relative to the unit cell). Figures 1(a) and 1(b) show
Later, in the Seventeenth Century, a German chemist named Georg Ernst Stahl was the first to postulate on chemical reaction, specifically, combustion. He said that a substance called phlogiston escaped into the air from all substances during combustion.
An enzyme is a protein that acts as a catalyst to form reaction, and see the activity of the
Enzymes are biological catalysts that facilitate specific chemical reactions (Raven, et al., 2014). Enzymes do their job by
2. A catalyst is a chemical agent that speeds up a reaction without being consumed by the reaction.
3. Cells use enzymes as biological catalysts to increase or accelerate the rate of reactions, such as those in photosynthesis or glycolysis. This allows reactions to occur under conditions that sustain life.
2. What are catalysts? What is a type of catalyst and why is it needed?
Enzymes are substances that play a role as a catalyst in order to induce a specific reaction. The enzyme we have chosen is carbamoyl-phosphate synthase 1. This enzyme is a mitochondrial enzyme
Chemical reactions occur every day almost continuously, both in the natural world outside as well as inside living organisms. These reactions occur at varying speeds, but are usually considerably slow. Some reactions can take as long as seven years for the molecules to undergo the reaction process (Berenbaum 153-154). However, with the presence of an enzyme in the reaction, this process speeds up considerably. A reaction that takes seven years to complete, now takes less than a second to finish (Berenbaum 154). With the help of these enzymes, chemical reactions are sped up to where they are able to help with the natural processes of the world.
My participation in the SURC conference will allow me to practice sharing the findings discovered in my research in Dr. Ferreira's lab for the investigation of the photoredox catalysis. This practice will be valuable for my growth as a researching scientist, who will be practicing research and presenting the work to others in the future. Attending this conference would enable me to continue practicing this pertinent skill in the realm of research. My involvement with the conference would be great practice from the usual presentations in the lab group meeting as I must be able to articulate the purpose and data to scientists, who may be unfamiliar with organometallic catalysis and the efforts towards synthetic method development. This topic of research was not widely represented at SURC the previous year, and the exhibition of my research would add to the overall diversity of the types of research presented at SURC.
Addition of rare earth metals, especially Lanthanum (La), to ceria supports has been widely investigated. Rare earth metals are well known for their catalytic effects, and when added to ceria catalyst, provide improved thermal stability and increased activity [Wang et al., 2010]. Wang et al. (2011) studied a ceria/zirconium catalyst doped with rare earth metals La, Nd, Pr, Sm, and Y and reported that all of the metals exhibited increased activity and selectivity with La, Nd, and Pr performing the best. Gold/ceria catalysts have also been subjected to rare earth metal doping and doping with Lanthanum and Gadolinium have both shown increased catalytic acfor 48 h [33,104]. The addition of Co to Mo/C was studied by
The mechanisms are identical to those of chemical catalysts, and thus comes forth
Chemical research is not a new practice. The beginnings of chemical research began thousands years ago. (1) Throughout the history of chemical research, many discoveries have been made, but none without cost. Nothing about chemical research is free. The is because, according to current economic theory nothing is free. There is always an opportunity cost, something given up, in order for anything to be done. This principle applies to anything researched. For example, under economic costing,to research the affects of ammonia on skin, not only does the cost of the chemicals, skin, and salary of the employee apply in the economic cost of research, but also the cost
Biological catalysts are our body’s tool box they break up or construct the necessary requirements our body’s requires to be able function on a daily basis. (Unknown,2015) Each enzyme has a unique job in our body without them small things such as digesting our food or even breathing in air would be extremely hard to complete. (Unknown,2012) Enzymes have specific substrates which they bind to on their active side. They also have specific temperatures and PH levels in which they work the best at. Once you place an enzyme in a temperature or PH level that they are not used to you deactivate them. Enzymes are also important factors to plants they speed up the
Catalytic Solutions, Inc. (CSI) was founded in Santa Barbara, California, in 1996 by Steve Golden and Bill Anderson. Being a young company, CSI is still in a “pre-profit” stage of operation that is why its performance measurement and incentive systems are primarily based on nonfinancial. For the first few years, CSI had developed innovative catalytic converters to the automobile market, which are used to reduce the pollution caused by combustion engine. CSI owns a technology that allows it to produce better performance and cheaper catalytic converters than competitors did.
Wilson and de Groot have investigated the surface reorganisation of a model Co catalyst upon exposure to 4 bar of a H2/CO mixture (2:1 ratio) at 523 K.10-11 The surface was examined ex-situ in an Ultra High Vacuum (UHV) chamber before and after exposure to syngas using a Scanning Tunnelling Microscope (STM). Before exposure to CO the surface consisted of flat terraces, with a Co(0001) structure. The terrace surfaces were separated by cliff edges ranging in size from single atom high steps