Formic acid

　　Reducing agent. Used for the determination of arsenic, bismuth, aluminum, copper, gold, indium, iron, lead, manganese, mercury, molybdenum, silver, and zinc. Identification of cerium, rhenium, and tungsten. Testing of aromatic primary and secondary amines. Determination of relative molecular mass and crystallization solvents. Determination of methoxy groups. Used as a fixative in microanalysis. Manufacture of formates.

　　Main Applications

　　Agriculture:

　　Silage preservative: Formic acid inhibits the growth of molds and spoilage bacteria in silage, extending storage life and preserving nutritional content (addition amount 0.5%-1.5%).

　　Crop fungicide: Low-concentration formic acid (1%-3%) is used to control wheat powdery mildew and fungal diseases in fruit trees, replacing some highly toxic pesticides.

　　Leather and Textile Industry:

　　Leather unhairing and tanning: Formic acid acts as an acidic regulator, adjusting the pH of the tanning liquor (3-4), promoting the binding of tanning agents (such as chromium salts) to skin collagen, and improving leather softness.

　　Textile dyeing auxiliary: Used in acid dyeing to improve the adsorption of dyes on fibers and enhance color fastness.

　　Chemical and Energy:

　　Organic synthesis intermediate: Used in the synthesis of methyl formate (solvent), formamide (pharmaceutical raw material), caffeine, etc.

　　Fuel cell fuel: Formic acid is easily oxidized (reaction: HCOOH→CO₂+ 2H⁺+ 2e⁻), serving as the fuel for Direct Formic Acid Fuel Cells (DFAFC), offering high energy density and lower toxicity than methanol.

　　Pharmaceuticals and Food:

　　Pharmaceutical intermediate: Synthesis of drugs such as Metamizole and Vitamin B1.

　　Food additive: Used as a preservative (limited use allowed by GB 2760) to inhibit microbial growth in food.