Plastics are synthetic or natural polymers that are widely used in industrial fields and daily life due to its good durability and plasticity.Among plastics,polyethylene terephthalate (PET) is the most commonly used.Polyethylene terephthalate (PET) is one of the commonly used plastics,which is widely used in many fields.PET is difficult to be degraded under natural circumstances without artificial treatment,which brings serious burden to the ecosystems,so the issue of degradation and regeneration of PET plastics has become a hot issue globally.Many methods such as photodegradation,thermal degradation,biodegradation,etc.,have been developed to degrade plastics.Among them,biodegradation is considered as environmental friendly and highly efficient method.Thus,the design and transformation of PET degradation has become a key issue.The main methods for degrading plastics at the present stage,the common enzymes used for degrading PET by biodegradation methods and the modification methods of PET degrading enzymes are reviewed,to provide a theoretical basis for the rapid degradation and regeneration of PET.

A series of B?MFI zeolites were synthesized using a solvent?free method using tetrapropylammonium hydroxide (TPAOH) as a template. XRD, SEM, N₂ adsorption desorption, in situ infrared spectroscopy, and pyridine adsorption infrared spectroscopy were used to characterize the effect of template agent addition on the physicochemical properties of B?MFI zeolites, and the performance of 1?butene double bond isomerization reaction was investigated. The results showed that the addition of template significantly affected the grain size and skeleton boron species content of B?MFI zeolites. When the template agent addition was 4.500 g (n（SiO₂）/n（TPAOH)=11.6）, the B?MFI zeolites obtained had the smallest particle size and the largest number of silicon boron hydroxyl pits, providing more highly active reaction sites. The reaction evaluation results confirmed that when using B?MFI molecular sieve catalyst for the double bond isomerization of 1?butene, the conversion rate of 1?butene was as high as 70.00%, and the selectivity of 2?butene was greater than 99%. The catalyst had excellent stability and showed no signs of deactivation during the evaluation period.