can't read?
Molybdenum is a chemical element with symbol Mo and atomic number 42. Molybdenum does not occur naturally as a free metal on Earth; it is found only in various oxidation states in minerals.
Molybdenum is used in NO, NO2, NOx analyzers in power plants for pollution controls. At 350 °C (662 °F), the element acts as a catalyst for NO2/NOx to form NO molecules for detection by infrared light.