Boosting tribo-catalytic conversion of H_(2)O and CO_(2)by Co_(3)O_(4)nanoparticles through metallic coatings in reactors

In recent years,more and more metal oxides have been finding critical tribo-catalytic applications.Presently,we have explored the tribo-catalytic conversion of H_(2)O and CO_(2)using Co_(3)O_(4)nanoparticles and obtained some surprising results.In an as-received 150 mL glass reactor enclosed with 10 mL of H_(2)O,0.10 g of Co_(3)O_(4)nanoparticles,1 atm of CO_(2),and a Teflon magnetic rotary disk,we observed the production of as much as 57.41μmol/L of H_(2),0.15μmol/L of CH_(4),and 0.21μmol/L of CO after 5 h of magnetic stirring.Metallic coatings of Cu,Ni,SUS316,Ti,Nb,Mo,and W were further introduced on reactor bottoms separately.For those coatings of Ni,SUS316,Ti,and Nb,the reduction of CO_(2)was dramatically enhanced,and C_(2+)products of C_(2)H_(6)and C_(2)H_(4)were observed.Especially for the Ti coating,the amounts of H_(2)and CH_(4)were increased by 2 and 26 times from those for the glass bottom,respectively,and the amounts of C_(2)H_(6)and C_(2)H_(4)were very impressive.The Co_(3)O_(4)nanoparticles were proven chemically stable under magnetic stirring in water,and hydroxyl radicals and superoxide radicals have been detected for the Co_(3)O_(4)nanoparticles under magnetic stirring through fluorescence spectroscopy and electron paramagnetic resonance spectroscopy analyses.These findings not only reveal outstanding capability of Co_(3)O_(4)to generate multicarbon products from H_(2)O and CO_(2)through tribo-catalysis but also highlight a promising potential of tribo-catalysis as a whole to harness mechanical energy for addressing energy shortages and environmental pollution.