Mining and extracting metals from hard rock adversely impact the environment. These impacts could be mitigated by capturing dissolved metals from water (i.e., mine runoff, industrial wastewaters, or even tap water) and converting the metals to products with potential economic benefits (i.e., upcycled into high-value products). We sought to identify a sorbent that can remove dissolved metals from water and in the process of this low-temperature surface adsorption create a catalytic material of potential economic value. We discovered that γ-aluminum oxide (γ-Al 2 O 3 ) can produce a reactive catalyst after removing metal ions (copper (Cu), palladium (Pd), nickel (Ni), and cobalt (Co)) from water, even for dissolved metals at environmentally relevant concentrations. The resulting metal-coated γ-Al 2 O 3 behaved, comparable to high-temperature produced catalysts, as a mono-or bimetallic catalyst capable of oxidizing or reducing pollutants (methylene blue, 4-nitrophenol, nitrite, and nitrate). Mono-or bimetallic catalysts synthesized from tap water with metal ions present efficiently oxidized methylene blue (by Cu/γ-Al 2 O 3 ) or reduced nitrate (by Pd−Cu/γ-Al 2 O 3 ) into less harmful species (i.e., ammonium and dinitrogen gas). Results demonstrated the versatile use of γ-Al 2 O 3 that removes metal ions from water (i.e., water purification) and produces a valuable γ-Al 2 O 3 -based byproduct with proven catalytic reactivity (i.e., catalyst production) and commercial markets.