Tetraphenylporphinatoaluminum chloride ((TPP)AlCl) catalyst and tetra-n-butylammonium bromide (TBAB) cocatalyst system is effective in copolymerizing CO₂ and oxetane. Hiroshi Sugimoto and colleagues present a report on PTMC formation with an excellent ratio of carbonate linkages from oxetane and CO₂. The details found in the article on page 3122 may open new doors for further development of the synthesis of polycarbonate from CO₂. (DOI: 10.1002/pol.20210536)

The electrochromic supercapacitor constructed by poly(1H-benzo[g]indole)/TiO2 nanocomposites with nanorod array morphology shows good electrochromic performance and energy storage capability. The work from Guangming Nie and colleagues on page 3100 can provide a way to intelligently monitor the energy storage state of the device through reversible color change or transmittance change. (DOI: 10.1002/pol.20210591)