ERIC Number: EJ1148303
Record Type: Journal
Publication Date: 2017-Jul
Abstractor: As Provided
Facile Method to Study Catalytic Oxygen Evolution Using a Dissolved Oxygen Optical Probe: An Undergraduate Chemistry Laboratory to Appreciate Artificial Photosynthesis
Renderos, Genesis; Aquino, Tawanda; Gutierrez, Kristian; Badiei, Yosra M.
Journal of Chemical Education, v94 n7 p922-927 Jul 2017
Artificial photosynthesis (AP) is a synthetic chemical process that replicates natural photosynthesis to mass produce hydrogen as a clean fuel from sunlight-driven water splitting (2H[subscript 2]O [right arrow] O[subscript 2] + H[subscript 2]). In both natural and artificial photosynthesis, an oxygen-evolving catalyst (OEC) is needed to catalyze oxygen production from water (2H[subscript 2]O [right arrow] O[subscript 2] + 4H+ + 4e--). Herein, we present a simple undergraduate laboratory experiment for monitoring the catalytic oxygen-evolution reaction using a dissolved oxygen optical probe, a luminescent probe that can continuously measure the concentration of dissolved oxygen in aqueous solutions. The laboratory experiment consists of two parts. First, students identify and evaluate the necessary criteria for an active molecular O[subscript 2]-evolving catalyst. Second, students use a kinetic protocol based on the method of initial rates to derive an empirical rate law expression and calculate the turnover frequency and rate constant for a benchmark OEC, [Ru[superscript II](tpy)(bpy)(H[subscript 2]O)][superscript 2+] (tpy is 2,2':6',2"-terpyridine; bpy is 2,2'-bipyridine). The use of simple transition metal complexes allows students to easily grasp how the choice of transition metals and the coordinated organic ligands can greatly impact the overall catalytic performance. Students collect time-dependent dissolved oxygen plots, and analyze and interpret oxygen-evolution data using modern equipment. This laboratory protocol is simple, and allows students to relate many fundamental topics such as thermodynamics, kinetics, redox and coordination chemistry, and catalysis to advances in current chemical research to help broaden their understanding of artificial photosynthesis.
Descriptors: Science Instruction, College Science, Undergraduate Study, Chemistry, Kinetics, Hands on Science, Scientific Concepts, Science Experiments, Laboratory Experiments, Science Laboratories, Metallurgy, Thermodynamics, Molecular Structure
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: firstname.lastname@example.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education; Postsecondary Education
Sponsor: Department of Education (ED)
Authoring Institution: N/A
Grant or Contract Numbers: PO31C160038