Ammonium nitrate

Ethanol synthesis via di-Me oxalate hydrogenation has garnered increasing attention in the fields of syngas utilization.Although ε-Fe₂C has been identified as a promising active species for DMO hydrogenation to ethanol, its formation is kinetically challenging during carbonization.In this work, a Fe₄N phase was first synthesized by pretreating a 30Fe/SiO₂ catalyst in an ammonia environment, followed by carbonization in a methanol-H₂ flow to obtain ε-Fe₂C as the active phase.Fe₄N, rather than Fe-O-Si, facilitates the transformation into iron carbide during the carbonization process.The transformation pathway of iron nitride (Fe_xN) is mediated by intermediate iron carbonyl species (Fe-CO), ultimately leading to the formation of iron carbide as the active phase.The resulting catalyst exhibited 40 times higher catalytic activity than the untreated catalyst in DMO hydrogenation.Combined structure properties and DFT calculation revealed that the lower energy barrier of ε-Fe₂C for ester hydrogenation underpins/strengthens its superior performance, while the STY of ε-Fe₂C is 2.8 times that of ε-Fe_2.2C and 58 times that of χ-Fe₅C₂.This study provides a novel strategy for designing highly efficient iron carbide catalysts for the esters hydrogenation system.

Amid global food shortage, alternative cost-effective protein sources are urgently needed for aquaculture and animal feed. Without a rigid cell wall, Euglena gracilis provides extractable, digestible proteins, and its high productivity makes it an ideal feed source. This study investigates the effects of different inorganic nitrogen sources on the biomass and biochemical composition of E. gracilis, and discusses the mechanisms of its nutrient transformation via proteomics. Results show ammonium nitrogen optimizes growth and protein accumulation by serving as an energy-efficient precursor for biomolecule synthesis compared to nitrate. Additionally, sulfate supplies sulfur for amino acid synthesis, and ammonium sulfate further enhances protein production. Under high-protein conditions, lipids and pigments increase while paramylon decreases significantly, underscoring nitrogen's role in carbon allocation and energy metabolism. This study establishes a metabolic framework for nitrogen-sulfur coordinated regulation of protein synthesis in E. gracilis, paving the way for its industrial application as a next-generation protein resource.