A comparative life cycle assessment of Pt nanoalloy/carbon nitride/graphene electrocatalysts for PEMFC stacks
Giovanna Paladin, Alessandro Manzardo, Angeloclaudio Nale, Enrico Negro, Vito Di Noto
Abstract
• The environmental impacts of a PtX n nanoalloy (X = Cu and/or Ni)/Carbon Nitride/Graphene electrocatalyst (EC) for the ORR are analyzed. • The new EC reduces the overall Pt loading of proton-exchange membrane fuel cells (PEMFCs). • The environmental impacts of PEMFC stacks including either the new EC or a conventional EC are compared. • The environmental impacts are reduced by curtailing the Pt loading in the PEMFC stack. The present work compares the potential environmental impact of two proton-exchange membrane fuel cell (PEMFC) stacks using life cycle assessment (LCA) methodology. The two PEMFC stacks yield the same output power, even if they have a different electrocatalyst (EC) to promote the oxygen reduction reaction (ORR). The two investigated ECs are: (i) a state-of-the-art Pt/C EC; and (ii) an innovative hierarchical PtX n nanoalloy (X = Cu and/or Ni)/Carbon Nitride/Graphene “core – shell” EC, labelled hereinafter “PtX n -CN/Gr” . The latter is enabled by graphene and related materials (GRMs). The features of the PEMFC stacks in terms of functional components, operating conditions and performance are modeled on experimental results obtained from pilot devices. The contributions of the various functional components included in the PEMFC stacks ( e.g. , the ECs, the proton-exchange membrane and the gas-diffusion layers) are quantified explicitly. The potential impact categories results are investigated through (i) a Monte Carlo analysis, to determine their uncertainties, and (ii) a sensitivity analysis, to verify their relationship with the modelling parameters ( e.g. , the source of platinum and the scale of the synthetic process leading to the ECs). Finally, on the basis of the analysis of LCA results, a number of avenues are proposed to minimize the potential environmental impact of PEMFC systems