Microfibrous-structured nanoporous gold (NPG) on Al-fiber catalysts, obtained by galvanic deposition onto a 3D network using 50 μm Al-fiber, is cost-effective (low Au-loading, e.g., 1 wt%), highly active/selective (>90% selectivity at >50% conversion) and stable (at least 300 h without NPG sintering) for oxidative coupling of methanol to methyl formate.