| abstract |
A catalyst, wherein the catalyst uses molybdenum (Mo) as an essential element, and other constituent elements in the catalyst active component satisfy the relationship represented by the following formula (cI), 0.44≤Σ{(MoIE-XIE)×XC} ≤1.53 (cI) [In formula (cI), XIE represents the first ionization energy (eV) of each element other than molybdenum, MoIE represents the first ionization energy (eV) of molybdenum, and XC represents the molybdenum as 12 The atomic ratio of this element in the case of (MoIE-XIE) is less than 0, and (MoIE-XIE) is used for the calculation as 0]. |