Application of Gold Catalysts in Industrial Hydrogenation Process
Figure 1: SEM images of gold nanoparticles
The basic process of hydrogenation has been used as an organic chemistry reaction to add hydrogen gas to compounds for various applications.
While this process typically occurs in the presence of catalysts such as nickel or platinum, the use of gold as an alternative has drawn considerable attention from researchers, with nano-gold catalysts being cited as a potential way to drive innovative solutions.
Hydrogen is considered a high-purity and high-quality product suitable for a range of different applications, from replacing natural gas for heating to being used in engineering for innovative solutions in chemical production and photocatalytic energy capture.
Hydrogenation, originally used to recover oil from coal, was discontinued in the early 1950s due to high costs and was not revived until after the second oil crisis.
The Emergence of Gold Catalysts
Innovative catalysts that enhance the hydrogenation process have been investigated, such as gold nanoparticles for heterogeneously catalyzed reactions. The inclusion of elemental gold in this emerging field of selective hydrogenation is due to its desirable property of having the highest energy barrier for hydrogen dissociation.
Gold was initially considered an ineffective and inactive catalyst, possibly because conventional catalyst preparation methods produced gold particles outside the nanometer size range required for effective activity. Larger gold particles were unable to chemisorb reactant molecules, making the material considered a rather inactive catalyst.
However, researchers had previously tested the use of gold for heterogeneous catalysis in experiments conducted in the 1970s, illustrating gold's ability to catalyze hydrogenation, oxidative dehydrogenation, hydrogen exchange, and hydrocracking. This activity of gold catalysts is considered inferior compared to more traditional catalysts such as platinum and palladium and thus has not been explored as a good catalytic competitor.
Interestingly, the use of gold nanoparticles revived the concept of using gold as a catalyst, leading to a major discovery in 1980. The researchers found that the deposition of gold as nanoparticles by deposition-precipitation and co-precipitation accounted for its activity for CO oxidation at various temperatures ranging from ambient to -76°C.
This transformation led to the study of gold as an active catalyst and relevant scholars found that gold chloride was the most effective catalyst for the hydrochlorination of ethane.
The Gold Catalyst for Hydrogenation
As mentioned earlier, gold's limited capacity for chemisorption (such as hydrogen chemisorption) compared with platinum group metals also means that its performance as a catalyst for reactions including hydrogen dissociation will not be outstanding.
While this is true for gold in its amplified state, studies have shown that the size of a gold particle reflects its activity level and that hydrogen chemisorption depends on particle size. Furthermore, as the particle size is reduced to the nanoscale, gold nanoparticles are considered to be highly reactive and can be used as radiolabels and targeted cancer therapy.
When gold nanoparticles are used on reducible oxides, they also exhibit some excellent properties, especially their hydrogenation activity. Binding to gold catalysts can take various forms, including ordered mesoporous carbons, as they have similar structures in the fine chemical industry as well as in new energy technologies including biomass conversion and fuel cells.
Other researchers, including engineers, have begun to study gold catalysts because of their selectivity in order to produce specific results for innovative engineering solutions in the hydrogenation process.
The goal of his research group is to focus on the synthesis and characterization of materials in order to develop new catalytic reactions using gold, titania, and other metal additives as hydrogenation catalysts. This will help to understand the surface chemistry of gold, an area of research made up of many conflicting findings on inertness levels - which will help in the development of industrial separation and purification reactions.
Environment Application
The future prospects of using gold catalysts in hydrogenation processes can be seen as promising, with researchers trying to study its surface chemistry in order to tune this material and improve its selectivity compared to more traditional active metals used as catalysts Compared to preparing materials with better effect. In addition, some people have studied the use of carbon and other supports for gold catalysts to improve the activity state of its hydrogenation reaction. These are very promising directions.
While research in this area is seen as challenging, some researchers have had considerable success using gold catalysts for hydrogenation reactions, which may have implications for real-world applications such as the decomposition of waste plastics. Significant influence. This will be important and critical both to the plastic pollution crisis and to reduce the environmental impact of ineffective wastewater purification on human health.
In addition, further research on gold catalysts for the compound deuterium oxide could also revolutionize this limited field, as this innovative research could contribute to the production of smaller, safer nuclear power plants.
Variations in gold catalyst applications illustrate its utility and potential for a more sustainable future, with real-world applications that could revolutionize technology and advance environmental research.
References
1. McEwan L, Julius M, Roberts S, et al. A review of the use of gold catalysts in selective hydrogenation reactions[J]. Gold Bulletin, 2010, 43(4). https://link.springer.com/ article/10.1007/BF03214999.
2.Psu.edu. (2021). Going gold: Engineers to investigate using gold as a catalyst in hydrogenation | Penn State University. Available at: https://www.psu.edu/news/engineering/story/going-gold-engineers-investigate-using-gold-catalyst-hydrogenation (Accessed: 27 December 2021).
3. Sun Y, Cao Y, Wang L, et al. Gold catalysts containing interstitial carbon atoms boost hydrogenation activity[J]. Nature Communications, 2020, 11(1): 4600. https://www.nature.com/articles /s41467-020-18322-x