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This study is aimed at booming intelligent polymers and their applications in catalysis, presenting an intelligent polymer catalyst with photo-mediated catalytic ability. This catalyst was fabricated with polymeric 2-acrylamide-2-methylpropylsulfonic acid (acidic moieties capable of catalytic hydrolysis) and photo-sensitive acrylamide-azobenzene prepared from the synthesis of 4-aminoazobenzene with acryloyl chloride. Under the radiation of ultraviolet light, this catalyst would undergo a change of cis/trans-conformation of azobenzene, causing alterable accessibility to the internal catalytic sites and as a result mediated catalytic ability. This catalyst presented significant catalytic ability at ambient conditions due to the trans-conformation of azobenzene which endorsed accessibility to the internal catalytic sites. Conversely, this catalyst showed limited catalytic ability under ultraviolet light, in response to the isomerization of the cis-conformation of azobenzene which inhibited the accessibility. In this way, this catalyst showed the photo-mediated catalytic ability. The suggestion of this polymer catalyst provides a prospect to optically modulate the catalytic proceedings, particularly for complicated processes. [ABSTRACT FROM AUTHOR]

This study was aimed at addressing the present challenge of cascade reactions, namely, how to furnish the catalysts with desired and hierarchical catalytic ability. This issue was addressed by constructing a cascade-reaction nanoreactor made of a bifunctional molecularly imprinted polymer containing acidic catalytic sites and Pt nanoparticles. The acidic catalytic sites within the imprinted polymer allowed one specified reaction, whereas the encapsulated Pt nanoparticles were responsible for another coupled reaction. To that end, the unique imprinted polymer was fabricated by using two well-coupled templates, that is, 4-nitrophenyl acetate and 4-nitrophenol. The catalytic hydrolysis of the former compound at the acidic catalytic sites led to the formation of the latter compound, which was further reduced by the encapsulated Pt nanoparticles to 4-aminophenol. Therefore, this nanoreactor demonstrated a catalytic-cascade ability. This protocol opens up the opportunity to develop functional catalysts for complicated chemical processes. [ABSTRACT FROM AUTHOR]

This study is aimed at addressing the present challenges of self-controlled processes in tandem catalysis. Inspired by the opening and closing switchable behaviors of stomata in plant leaves arose by temperature, the objective is met by originally developing a "smart" tandem catalyst capable of crossing-response properties. The catalyst consisted of two unique functional layers where each may self-govern one coupled process. The first layer was fabricated with a negatively-thermosensitive imprinted polymer and encapsulated metal nanoparticles (PDEA- co -PAM/Ag) which were responsible for a catalytic reduction process. The second layer was made of a positively-thermosensitive polymer (PVI- co -PAMPS) with acidic groups, which were capable of a catalytic hydrolysis process. At low temperatures, this catalyst would conduct only catalytic reduction because of the open channel in the first layer. In middle temperatures, the catalyst would run the tandem processes from catalytic reduction to hydrolysis because of the open channels in both the two layers. At higher temperatures, the catalyst only catalyzed hydrolysis because of the closed channel in the first layer. In this way, the smart bi-layer catalyst achieved the single/tandem/single catalysis featured with a dual temperature-responsive switch. The novel protocol not only provides a new solution to complicated catalytic processes but also inspires the further application of smart polymers in a broader spectrum of areas. The switchable mechanism of the polymer reactor. [Display omitted] • Thermo-sensitive tandem catalyst is able to adapt to the changing environment. • A "smart" tandem catalyst is capable of crossing-response properties. • The catalyst is able to conduct the single/tandem/single reactions in different temperatures. • New catalyst shares a promising prospect to the development of one-pot catalytic processes in applications. [ABSTRACT FROM AUTHOR]