Heterogeneous Catalytic Reduction for Water Purification: Nanoscale Effects on Catalytic Activity, Selectivity, and Sustainability

This chapter reveals that the reductive catalysis is a promising water treatment technology that employs heterogeneous metal catalysts to convert dihydrogen to adsorbed atomic hydrogen in order to promote reactions with functional groups in various contaminants. Reductive catalysis has several potential advantages, including high selectivity for a given target, fast rates under mild conditions, and low production of harmful by-products. The technology has been applied mostly for remediation of groundwater contaminated with halogenated hydrocarbons and for treatment of nitrate, but recent studies has expanded the range of target contaminants to include perchlorate and N-nitrosamines. Palladium-based catalysts hold tremendous promise for their ability to selectively destroy several drinking water contaminants, and some compounds that exhibit slow reaction kinetics with Pd alone are rapidly degraded when a second, promoter metal is added to the catalyst. However, there is a lack of information about the long-term sustainability of these catalytic treatment processes, which is a major consideration in their possible adoption for remediation applications.