Scalable nanoporous carbon films allow line-of-sight 3D atomic layer deposition of Pt: towards a new generation catalyst layer for PEM fuel cells

Abstract

A self-supported, binder-free and scalable nanoporous carbon scaffold serves as an excellent host for the efficient and uniform atomic layer deposition of Pt nanoparticles, showing exemplary performance as a cathode catalyst layer in a PEM fuel cell.

Electrochemistry of new generation conformal polyaniline/carbon scaffolds with monodispersed nanopores and high capacitance

“…The slurry was then cast onto a glass substrate using a casting blade with a 0.003 inch (0.076 mm) gap between the doctor blade and the substrate. 14 After drying, pristine composite MP/PVA/PD/silica films were obtained. Six such films were then pressed together to form a single 6-layer film that was ca.…”

“…The final films were then inserted into a tube furnace (Thermo Scientific), held at 400 °C for 2 h, and then carbonized at 900 °C for 2 h in a N 2 atmosphere. 14…”

“…11–13 Largely for these reasons, we have developed a self-supported nanoporous carbon scaffold (NCS), which has shown significant promise in many applications. 14–17 The NCS, with its fully controllable, monodispersed, and 3-D interconnected nanopore size (ranging from 5 to 100 nm in diameter) and thickness (1 to 1000 μm), has been shown to be very useful as a novel Pt catalyst support, 14 as a microporous layer in PEM fuel cells, 15 and as a model structure for the investigation of liquid imbibition into nanoporous media. 16 The unique structure of the NCSs greatly facilitates the use of the material in practice both in flow-by and flow-through modes, thus generating higher mass transport rates (equating to higher currents) and allowing full utilization of the internal surface.…”

“…While the NCS has a very good gravimetric capacitance typical of mesoporous materials, ranging from 30 to 120 F g −1 in acidic solutions (0.5 M H 2 SO 4 , 2 mV s −1 ), as well as low tortuosity, 14,16 further improvements are required for capacitive applications where pore size control is desired, e.g. , for simultaneous membrane filtration and ion removal via capacitive deionization.…”

“…Therefore, the primary goal of the present work was to employ our scalable, mesoporous NCS material 14 as a binder-free substrate for the internal electrodeposition of a conformal PANI film. It was of particular interest to determine if the resulting capacitance would then increase as expected, indicating optimal solution access throughout the composite layers during charge and discharge.…”