Herein, we provide a study on the removal of volatile organic compounds (VOCs) using a metal-organic framework MIL-101(Cr) derived from PET waste, denoted as MIL-101(Cr)-PET. As a model molecule for VOCs frequently found in indoor air, toluene was used. The characteristics and adsorption efficiency of both conventional MIL-101(Cr), denoted as MIL-101(Cr)-BDC, and environmentally friendly MIL-101(Cr) powders were evaluated and compared using a range of techniques in our research, including PXRD, HAADF-STEM, TGA, BET, and adsorption studies. MIL-101(Cr)-PET exhibits crystal structure and thermal stability similar to the conventional MIL-101(Cr) synthesized using a commercially available organic linker. Differently, it displayed relatively agglomerated smaller particles and a reduced surface area, attributed to the absence of any modulator and the use of PET waste as the source of the organic linker. Nevertheless, similar toluene adsorption performance was obtained in both batch and continuous adsorption setups. Furthermore, the adsorption mechanism was elucidated by means of molecular simulation, identifying two distinct adsorption sites. At low toluene concentrations, the preferred site was within the small cage due to pore size constraints, while at saturation, the most likely conformation involved parallel offset staking. These results suggest the occupancy of less energetically favorable sites and volumetric filling at higher concentrations.