We study the electron relaxation processes in nanoporous Au structures using pump-probe thermoreflectance. Using a modified two temperature model, we determine that the electron Fermi relaxation time is unaffected by the ligament size and is an athermal process that is constant with laser pulse excitation, yet the electron-phonon relaxation is affected by boundary scattering and is dependent on electron temperature. The increased, temperature dependent electron-phonon coupling measurements can be explained by electron-boundary scattering and electron-electron scattering that alters the rate of electron equilibration with the surrounding media. These results lend insight into electron relaxation processes in high surface area nanostructures.

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