ZSM-5 zeolite is widely used in catalytic cracking of hydrocarbon, but the conventional ZSM-5 zeolite deactivates quickly due to its simple microporous and long diffusion pathway. Many studies have been done to overcome these disadvantages recently. In this review, four main approaches for enhancing the catalytic performance, namely synthesis of ZSM-5 zeolite with special morphology, hierarchical ZSM-5 zeolite, nano-sized ZSM-5 zeolite and optimization of acid properties, are discussed. ZSM-5 with special morphology such as hollow, composite and nanosheet structure can effectively increase the diffusion efficiency and accessibility of acid sites, giving high catalytic activity. The accessibility of acid sites and diffusion efficiency can also be enhanced by introducing additional mesopores or macropores. By decreasing the crystal size to nanoscale, the diffusion length can be shortened. The catalytic activity increases and the amount of carbon deposition decreases with the decrease of crystal size. By regulating the acid properties of ZSM-5 with element or compound modification, the overreaction of reactants and formation of carbon deposition could be suppressed, thus enhancing the catalytic activity and light alkene selectivity. Besides, some future needs and perspectives of ZSM-5 with excellent cracking activity are addressed for researchers’ consideration.

Many useful materials can be prepared by the self-assembly of oligopeptides. The design rules around such peptides are relatively established and they assume well-defined and pure materials. In many cases however, the purity of the peptide is less than 95%, and the ability of likely impurities to self-assemble is an open question. Here, we discuss the self-assembly of the gel-forming octapeptide FEFEFKFK and two analogues, EFEFKFK and FEFEfKFK, to examine the effect of an amino acid deletion and of epimerization at one position. Both the truncated peptide and epimerized peptide can still form gels. Mixing these peptides with the parent FEFEFKFK leads to the formation of new, but different, self-assembled structures. This has direct implications for our understanding of the necessary design rules for self-assembly regarding the influence of potential impurity in these systems, as well as demonstrating that much remains to be learned about sequence to structure relationships in self-assembling peptide systems.