γ?Al₂O₃ is commonly used as a carrier for catalysts, and the physicochemical properties of its surface greatly influence the catalytic reaction. The exposed Al coordination environment can be regulated by adjusting the morphology of γ?Al₂O₃ carriers by changing the synthesis method and synthesis conditions. The energy of the exposed crystal lattice of carriers with different morphologies is different, which will directly affect the acidity of the carrier and the interaction between active metals, and active metals and carriers, thus creating different loading sites of active metals. Carrier morphology control is an effective way to regulate the structure of the active components. The regulation of the support morphology of the propane dehydrogenation catalyst will affect the catalytic performance. The research progress of γ?Al₂O₃ support was reviewed from the aspects of preparation method, morphology control, and its influence on propane dehydrogenation catalyst.

Conductive polymers have attracted the interest of scientific researchers due to their high electrical conductivity,light weight,corrosion resistance,and good electrical and optical properties.As a typical conductive polymer,polypyrrole has attracted much attention because of its simple synthesis conditions,good environmental stability,environmental friendliness,and the wide range and tunability of electrical conductivity.However,it suffers from some shortcomings such as difficulties in dissolution and melt and poor mechanical properties and processing properties,which limit its application.Composites formed by polypyrrole and other materials not only improve the original shortcomings of polypyrrole but also combine the advantages of the two to endow the materials with new properties and broaden their application fields.This paper briefly described the main synthesis methods of polypyrrole,analyzed the advantages and disadvantages of each method,and summarized its applications in the fields of supercapacitors,gas sensors,and biological tissue engineering.The paper also discussed the problems facing polypyrrole composites and corresponding solutions and provided an outlook on their future development.