Highly efficient and selective partial reduction of nitroarenes to N-arylhydroxylamines catalysed by phosphine oxide-decorated polymer immobilized ionic liquid stabilized ruthenium nanoparticles

•Ultrafine RuNPs stabilised by a phosphine oxide-modified polymer immobilized ionic liquid.•Complete selectivity for the partial reduction of aromatic and heteroaromatic nitroarenes to the corresponding N-arylhydroxylamine.•Highest initial turn over frequency to be reported for a RuNP catalysed partial reduction of nitrobenzene to N-phenylhydroxylamine.•Reduction of electron rich amino nitroarenes to the aniline proposed to occur via a quinondiimine-derived iminium.•High activity and selectivity retained over five reuses with only a minor reduction in conversion.