(20d) CO2-Responsive Polymer Supported Au Used As Easily Reusable Catalyst in Aqueous Media Conference: AIChE Annual MeetingYear: 2015Proceeding: 2015 AIChE Annual MeetingGroup: Catalysis and Reaction Engineering DivisionSession: Green Chemical Reaction Engineering for Sustainability Time: Sunday, November 8, 2015 - 4:30pm-4:50pm Authors: Wang, W. J., Zhejiang University Zhu, S., McMaster University Zhang, Y., Zhejiang University Li, B. G., Zhejiang University Gold catalysts have an outstanding catalytic activity when well dispersed in its nanoparticle form (<10nm). In this work, we developed a series of CO2-responsive star polymer-supported Au as easily-recyclable catalysts in water by simply bubbling CO2 and N2. The polymers consisted of a hyperbranched polyethylene(HBPE) core and multiple poly(2-(dimethylamino)ethyl methacrylate-2-(Diethylamino)ethyl methacrylate) (PDMAEMA-DEAEMA) arms, and were synthesized through a sequential Pd-catalyzed chain walking copolymerization of ethylene and 2-(2-bromoisobutyryloxy)ethyl acrylate, followed by atom-transfer radical polymerization with DMAEMA and DEAEMA. The samples had a molecular weight between 12-40kg/mol with fDMAEMA/DEAEMA making up 41-74 wt%, and could be easily dispersed in water to form micelles of several hundred nanometers. The catalysts were used for the reduction of 4-nitrophenol in water, and were recycled by purging CO2/N2. Catalysts with fDMAEMA/DEAEMA making up 45-65wt% performed well, however higher values may have prevented reactant contact with the Au catalyst. The catalysts can be reused several times (up to 15 times) with a concentration of approximately 15ppm and with very little catalysis activity loss. These catalysts demonstrated higher catalytic activity than previously reported supported Au catalysts and good CO2 switchability.