Pengaruh textural promotor (Al2O3, SiO2, MgO) pada katalis berbasis Ni-Cu terhaap kualitas dan kuantitas nanokarbon melalui reaksi dekomposisi katalitik metana = Effect of textural promoter (Al2O3, SiO2, MgO) on Ni-Cu based catalyst to nanocarbon quality and quantity via catalytic methane