Dear Editor,Urea is a vital nitrogen(N)fertilizer in farmland soils and the natural intermediate product of various organonitrogen compounds,such as purines and amino acids(Mobley and Hausinger,1989;Glibert et al.,201...Dear Editor,Urea is a vital nitrogen(N)fertilizer in farmland soils and the natural intermediate product of various organonitrogen compounds,such as purines and amino acids(Mobley and Hausinger,1989;Glibert et al.,2014).Urea in soils is rapidly hydrolyzed to ammonium by urease secreted from ureolytic microorganisms,and then assimilated by plants and microbes or involved in other N cycling pathways,including aerobic and anaerobic ammoxidation(Mobley et al.,1995;Pajares and Bohannan,2016).展开更多
Plate-like MFI zeolite with a short b-axis length is highly desired for industrial applications,because the larger straight channels along the b-axis are a primary pathway for mass transfer.This work reports that guan...Plate-like MFI zeolite with a short b-axis length is highly desired for industrial applications,because the larger straight channels along the b-axis are a primary pathway for mass transfer.This work reports that guanidine compounds,such as tetramethylguanidine(TMG),dodecylguanidine hydrochloride(DGH),and polyhexamethylene biguanidine hydrochloride(PHMB),are more efficient for synthesizing these types of zeolites,needing neither a greater amount of water nor a longer crystallization period.Because of the modifiers used,the zeolite crystals with a thickness of 75–110 nm were obtained by crystallizing the gel with an H_(2)O/SiO_(2) mole ratio of 14 at 170℃ for 12 h.Moreover,the incorporation of Al and Ti into the ZSM-5 and TS-1 frameworks was also increased by the modifiers.展开更多
基金supported by the Funds for International Cooperation and Exchange of the National Natural Science Foundation of China(No.42020104003)。
文摘Dear Editor,Urea is a vital nitrogen(N)fertilizer in farmland soils and the natural intermediate product of various organonitrogen compounds,such as purines and amino acids(Mobley and Hausinger,1989;Glibert et al.,2014).Urea in soils is rapidly hydrolyzed to ammonium by urease secreted from ureolytic microorganisms,and then assimilated by plants and microbes or involved in other N cycling pathways,including aerobic and anaerobic ammoxidation(Mobley et al.,1995;Pajares and Bohannan,2016).
基金financially supported by the National Natural Science Foundation of China(Grant No.22076017).
文摘Plate-like MFI zeolite with a short b-axis length is highly desired for industrial applications,because the larger straight channels along the b-axis are a primary pathway for mass transfer.This work reports that guanidine compounds,such as tetramethylguanidine(TMG),dodecylguanidine hydrochloride(DGH),and polyhexamethylene biguanidine hydrochloride(PHMB),are more efficient for synthesizing these types of zeolites,needing neither a greater amount of water nor a longer crystallization period.Because of the modifiers used,the zeolite crystals with a thickness of 75–110 nm were obtained by crystallizing the gel with an H_(2)O/SiO_(2) mole ratio of 14 at 170℃ for 12 h.Moreover,the incorporation of Al and Ti into the ZSM-5 and TS-1 frameworks was also increased by the modifiers.
