Development of Metal-impregnated Single Walled Carbon Nanotubes for Toxic Gas Contaminant Control in Advanced Life Support Systems

The success of physico-chemical waste processing and resource recovery technologies for life support application depends partly on the ability of gas clean-up systems to efficiently remove trace contaminants generated during the process with minimal use of expendables. Highly purified metal-impregnated carbon nanotubes promise superior performance over conventional approaches to gas clean-up due to their ability to direct the selective uptake gaseous species based both on the nanotube’s controlled pore size, high surface area, and ordered chemical structure that allows functionalization and on the nanotube’s effectiveness as a catalyst support material for toxic contaminants removal. We present results on the purification of single walled carbon nanotubes (SWCNT) and efforts at metal impregnation of the SWCNT’s. INTRODUCTION CARBON MATERIALS ON SPACE HABITATS Carbon materials have long been used in environmental remediation and waste treatment for removal of toxic contaminants in both gaseous and liquid environments. On Space Station Mir, the air revitalization system included: (i) an expendable charcoal canister (weighing 6 Kg and having 1.3 Kg activated charcoal), (ii) two regenerable canisters (weighing 16 Kg each and having 7.4 Kg activated carbon each) and which are regenerated every 20 days, (iii) an ambient temperature catalyst containing 0.5 Kg of a precious metal catalyst, and Activated carbon has been extensively used due to a number of factors that include low-cost production and high surface area. However, some of the drawbacks to activated carbons are 1) non molecular defined chemical structure, 2) lack of specificity due to broad pore size distribution, 3) small pore volume and the associated low uptake weight for volatile gases, including NO, compounds. CARBON NAN0 TUBES (CNT)