Alginic acid-based metal monatomic catalyst as well as preparation method and application thereof

The invention discloses a preparation method of an alginic acid-based metal monatomic catalyst, which comprises the following steps: (1) dropwise adding a sodium alginate aqueous solution into a calcium chloride aqueous solution, and conducting sieving to form calcium alginate hydrogel; (2) soaking the calcium alginate hydrogel with hydrochloric acid, performing ultrasonic treatment, conducting dipping with a metal salt solution, and conducting drying to obtain alginic acid metal gel; and (3) calcining the alginic acid metal gel under nitrogen source gas, carrying out acid treatment, drying and grinding to obtain the alginic acid-based metal monatomic catalyst. The preparation method is simple, suitable for different transition metals and suitable for large-scale production, nitrogen source gas is adopted to replace organic nitrogen for nitrogen doping, and more gaps and larger specific surface area are formed. The invention also provides the alginic acid-based metal monatomic catalyst prepared by the method