リサイクル

[3201-10-09] Formation of Bio-Palladium Nanoparticles Using the Extremely Acidophilic Archaeon Sulfolobus tokodaii

^○Santisak Kitjanukit¹, Hirajima Tsuyoshi¹, Keiko Sasaki¹, Naoko Okibe¹ (1. Kyushu University)

司会: 松岡光昭（早稲田大学）

Keywords:Extremely acidophilic archaeon, Palladium, Bio-Pd(0) nanoparticles, Sulfolobus sp.

Despite the limited abundance in nature, the demand for palladium (Pd) to be used as a catalyst is increasing year by year. Therefore, development of effective recycling and production technology is important. Pd catalyst is often used today in the form of nanoparticles and its current production methods involve a number of steps using different chemical reagents. As a simpler and more environmentally-feasible approach, microbially facilitated production of Pd(0) nanoparticles is proposed here. This study investigated the utility of the extremely acidophilic archaeon, Sulfolobus tokodaii, as a support for the bio-Pd(0) nanoparticles production. The combination of microbial enzymatic reduction and the following chemical reduction (10 mM formate) enabled effective removal of Pd(II) ions from the solution, forming bio-Pd(0) nanoparticles on the cell surface within 5 hours. Living cells with active enzymatic activity were required to produce fine and well-dispersed bio-Pd(0) nanoparticles. Catalytic ability of bio-Pd(0) nanoparticles (evaluated through Cr(VI) reduction reaction) showed comparable efficiency to that of commercial Pd/C catalyst. In addition, effects of additional Cl^- were also investigated to study the possibility of applying this approach to the Pd-containing urban mine leachate.　Overall, the results demonstrated the potential of microorganisms to produce highly catalytic bio-Pd(0) nanoparticles using an environmental friendly approach.