On the role of N-methylmorpholine-N-oxide (NMMO) in the generation of elemental transition metal precipitates in cellulosic materials

Abstract Several literature reports describe the role of aqueous solutions N -methylmorpholine- -oxide monohydrate (NMMO) as a suitable medium for generation transition metal (nano)particles in or on cellulosic materials and further elaborate its co-reactant salts that are reduced to elemental metal. However, this would assign NMMO reductant, which is contradiction obvious oxidative nature. In present study, exemplary cases silver, gold, platinum precursors respective NMMO/cellulose mixtures were investigated. Naturally, did not act reducing agent any case—this was taken over by frequently used stabilizer propyl gallate, cellulose itself, into carbonyl carboxyl groups introduced. Also, hypochlorite—produced intermediately from chloride ions subsequently undergoing disproportionation chlorate—or transient -methylene(morpholinium) generated NMMO, turn oxidized formyl morpholide, can corresponding reductants while reduced, depending reaction conditions. Apart providing interesting mechanistic insights, study points importance precise description composition chemical systems used, well seemingly inert auxiliaries, turned out be essential co-reactants (nano)particle generation. Graphic abstract