Facile preparation of nanosized copper sulfide functionalized macroporous skeleton for efficient vapor-phase mercury sequestration

Abstract

The critical challenge to achieve cost-effective elemental mercury (Hg0) capture from coal combustion flue gas by using mineral sulfides lies in developing a facile method to realize their fixed-bed application, which hence exhausts the adsorption capacity of mineral sulfides and optimize their economic-sustainability. In this work, a feasible and facile synthesis procedure based on a one-step cetyltrimethylammonium bromide (CTAB) assisted precipitation procedure was proposed to overcome this challenge. During this process, the CTAB played a crucial role to effectively confine the particle size of copper sulfide (CuS) in nanoscale and stably anchor it over the macroporous polyurethane foam (PUF) skeleton. The macropore-enriched CuS/PUF as synthesized was merited for its high throughput morphology, nanoscale particle size of CuS, homogeneous distribution of active components, and multiform surface sulfur ligands, which is promising to be used in a fixed-bed scenario to achieve efficient Hg0 sequestration. These benefits co-derived an excellent Hg0 sorbent with extremely high uptake capacity and adsorption rate (265.6 mg g−1 and 2.16 mg g−1 min−1), exceeding those of other mineral sulfides and traditional activated carbons as reported in previous studies by folds, even by magnitudes. With such an outstanding Hg0 sequestration performance and a macroporous structure, it can be reasonably concluded that the CuS/PUF will be a potential sorbent to be adopted in a fixed-bed scenario, which optimizes the cost-effectiveness of mineral sulfide based sorbents and extend their application flexibility for the Hg0 adsorption from coal combustion flue gas.