Abstract:
CO2 conversion to valuable chemicals and fuels at
ambient temperature and atmospheric pressure using a sustainable
energy source is an attractive but challenging task. Herein, Zrthiamine is pyrolyzed with urea under N2 atmosphere to prepare
Zr-thiamine modified carbon nitride (Zr-Thia/g-CN) catalyst. The
catalyst exhibits optimum Lewis acidity and basicity to produce
excellent cyclic carbonate yields by the insertion reaction of CO2
into epoxide on a large scale under neat conditions in the absence
of any cocatalyst under traditional thermal catalysis in 6 h. The
catalyst exhibits similar cyclic carbonate yield under simulated light
(250 W Hg lamp, λ > 360 nm) in 24 h and, most importantly,
under sunlight in 12 h in the presence of a low amount of
cocatalyst (2.5 mol % with respect to epoxide) under ambient
temperature, 1 bar pressure, and neat conditions. The catalyst is efficiently recycled up to 5 cycles in traditional thermal catalysis and
photocatalytic conditions. The structure−activity relationship is established, and the reaction mechanism is proposed with the help
of CO2 adsorption, CO2 temperature-programmed desorption techniques, acidity−basicity measurements, optoelectronic properties,
control reactions, and catalytic activity data. The development of a single catalyst for catalyzing the same reaction under traditional
thermal catalytic and sustainable photocatalytic conditions will attract researchers of different disciplines.
