Studies On The Catalytic Properties Of Two-dimensional Materials And Single-atom Catalyst

With the development of science and technology,people's living standard is improving continuously,and the problem of energy shortage and the environmental pollution begin to attract the attention of the world.In the face of the increasing energy crisis and environmental pollution,the efficient catalyst is an effective solution to the energy and environmental problems.There are many problems of low efficiency,poor selectivity and so on in the catalysts which are widely used at present.The transition metal has been used as an important part in industry because of its high activity and high selectivity in catalytic reaction.However,due to the lack of transition metal resources and its high price,the optimization of transition metal catalysts has become a hot topic of scientific research.At present,the nano catalytic materials exhibit unique properties in the study,the related study received a lot of attention,Among them,two-dimensional materials catalysts show good activity and stability in important fields such as small molecule reaction,organic reaction and electrocatalysis.single-atom structure,activity of catalyst and reaction mechanism research has become an important field of scientific research.Therefore,the construction of nano-catalysts with special structures is an important means to solve the application of transition metal catalysts.In this paper,a variety of nano catalysts were reported and their synthesis and catalytic mechanism were studied.It mainly includes the following aspects:1.The CoN catalytic material with two-dimensional structure was synthesized by treating Co nanoparticles in ammonia gas,and showed good activity and selectivity in the hydrogenation reaction of CO2.Through in-situ infrared,XPS and other in-situ labeling methods,it is shown that CoNHx phase is formed in the reaction process,which greatly increases the activity of H on the catalyst surface,and thus forms HCOO*species with CO2,so as to improve the catalytic activity.2.Design and synthesis of a two-dimensional Rh-W bimetallic material,through the control of adding amount of W(CO)6 in the synthesis,we can implement different proportions of synthesis of bimetallic alloys,and through the use of CO instead of W(CO)6,we realized the Rh metal material with the two-dimensional structure,through contrast experiment,Rh-W double metal two-dimensional material showed good selectivity and activity,the effect of electron transfer between Rh and W metal and material two-dimensional structure is the main reasons of the fine catalytic performance.3.The Rh single-atom catalyst supported on CoO two-dimensional nanomaterial substrate was synthesized.In the hydroformylation reaction,a good selectivity was shown.Further theoretical research indicated that under the atmosphere of CO and H2,Rh atoms were induced to undergo structural reconstruction,which enhanced the adsorption of propylene and formed a special spatial configuration,thus increasing the selectivity of the reaction.