Glycerol Is Converted into Energy and Carbonyl Compounds in a 3D-Printed Microfluidic Fuel Cell: In Situ and In Operando Bi-Modified Pt Anodes

Author(s)

de Souza, Matheus B. C. ; Guima, Katia-Emiko ; Fernandez, Pablo S. ; Martins, Caue A.

• Document type: Journal article
• Source: ACS APPLIED MATERIALS & INTERFACES; v. 14, n. 22, p. 9-pg., 2022-06-08.

Abstract

The combination of energy and chemical conversion can be achieved by designing glycerol fuel cells. However, the anode must promote the reaction at onset potentials low enough to allow a spontaneous reaction, when coupled to the cathodic reaction, and must be selective. Here, we build a three-dimensional (3D)-printed glycerol microfluidic fuel cell that produces power concomitantly to glycolate and formate at zero bias. The balance between energy and the two carbonyl compounds is tuned by decorating the Pt/C/CP anode in situ (before feeding the cell reactants) or in operando (while feeding the cell with reactants) with Bi. The Bi-modified anodes improve glycerol conversion and output power while decreasing the formation of the carbonyl compounds. The in operando method builds dendrites of rodlike Bi oxides that are inactive for the anodic reaction and cover active sites. The in situ strategy promotes homogeneous Bi decoration, decreasing activation losses, increasing the open-circuit voltage to 1.0 V, and augmenting maximum power density 6.5 times and the glycerol conversion to 72% at 25 degrees C while producing 0.2 mmoL L-1 of glycolate and formate (each) at 100 mu L min(-1). Such a performance is attributed to the low CO poisoning of the anode, which leads the glycerol electrooxidation toward a more complete reaction, harvesting more electrons at the device. Printing the microfluidic fuel cell takes 23 min and costs similar to US$1.85 and can be used for other coupled reactions since the methods of modification presented here are applied to any existing and assembled systems. (AU)

• FAPESP's process: 18/20952-0 - Applied and fundamental studies of the electrochemical conversion of alcohols and CO2
• Grantee: Pablo Sebastián Fernández
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Regular Program Grants
• FAPESP's process: 17/11986-5 - Generation and storage of New Energy: bringing technological development for the country
• Grantee: Ana Flávia Nogueira
• Support Opportunities: Research Grants - Research Centers in Engineering Program