Realizing methanol synthesis from CO and water via the synergistic effect of Cu^(0)/Cu^(+)over Cu/ZrO_(2) catalyst

The optimizing utilization of ca rbon resources has drawn wide attention all over the world,while exploiting the high-efficiency catalytic routes remains a challenge.Here,a direct methanol synthesis route is realized from pure CO and H_(2)O over 10%Cu/t-ZrO_(2) catalyst,where the time yield of methanol is144.43 mmol mol_(Cu)^(-1)h^(-1)and the methanol selectivity in hydrocarbons is 100%,The Cu species highly dispersed in the t-ZrO_(2) support lead parts of them in the cationic state.The Cu^(+)sites contribute to the dissociation of H_(2)O,providing the H*source for methanol synthesis,while the formed Cu^(0) sites promote the absorption and transfer of H*during the reaction.Moreover,the H_(2)O is even a better H resource than H_(2) due to its better dissociation effectivity in this catalytic system.The present work offers a new approach for methanol synthesis from CO and new insight into the process of supplying H donor.

Zircon U-Pb geochronology,whole-rock geochemical,and Sr-Nd-Pb isotopic constraints on the timing and origin of Permian and Triassic mafic dykes from eastern North China Craton

This work reports an important episode of extensional,mafic magmatism that impacted the North China Craton(NCC)during the Permo-Triassic and influenced the evolution of this Craton.We sampled 30 representative mafic dykes cropping out in eastern NCC,within the Hebei Province,China.New zircon LA-ICP-MS U-Pb ages,geochemical,and Sr-Nd-Pb isotopic data for these mafic dykes identified them as typical dolerites formed between 211.9±1.3 and 263.9±2.6 Ma.The mafic rocks fall into the alkaline and calc-alkaline series.They are enriched in light rare earth elements,some large ion lithophile elements(e.g.,Rb.Ba,and Sr),K,and Pb,and depleted in Nb,Ta,and Ti.The dykes have high initial 87Sr/86Sr ratios(0.7034-0.7178),negative eNd(t)values(—2.2 to—5.9),and relatively constant initial Pb isotopic ratios,that are EMI-like:(206Pb/204Pb)i=16.39-16.74,(207pb/204pb)j=15.22-15.24,and(208Pb/204Pb)i_=36.66-36.86,respectively.Our results indicate that the Hebei Province dolerites were likely derived from magma gen erated through low-medium degree partial melting(3.0-20%)of an EMI-like garnet-lherzolite mantle source.The parental magmas fractionated olivine,clinopyroxene,and Ti-bearing phases with obvious crustal contamination during rapid ascent and dyke emplacement.Since the possible influence of subduction of the Yangtze Plate has been excluded,we propose a model for the origin of the investigated mafic rocks,involving the Pennian collision between the Siberian Block and the NCC.The mafic dykes of eastern NCC within Hebei Province formed during a period of crustal thinning in response to extension after the early Permian collision.

Zircon U–Pb dating,geochemical,and Sr–Nd–Pb–Hf isotopic constraints on the age and origin of intermediate to felsic igneous rocks at South Altyn,Xinjiang,China

As a part of a giant trending fault system in the Asian continent and one where a strong zone of left strikeslip fault is present,the Altyn Orogenic belt(AOB)has become an important focus for research.Magmatic rocks are widely distributed across the AOB.However,many investigations have focused primarily on Paleozoic igneous rocks;discussion of Mesozoic related igneous activity is often ignored.Here we present the result of studies of representative diorite and granite rocks outcropping in the AOB,within the Xinjiang Uygur Autonomous Region,South Altyn,China.We present new zircon LA-ICP-MS U-Pb age,geochemical,and Sr-Nd-Pb-Hf isotopic data for these sample suites,identifying them as typical igneous rocks formed between 238±1.5 and 238.8±1.1 Ma.The rocks that we studied fall into the alkaline series,also enriched in light rare earth elements(LREE),some large ion lithophile elements(LILE;e.g.,Rb,Ba,Sr,and K),Pb,Th and U,and depleted in heavy rare earth elements(HREE),Nb,Ta,Hf,and Ti.The granite and diorite have high initial 87Sr/86Sr ratios(0.7062-0.7114),negativeεNd(t)values(-8.8 to-11.3),εHf(t)values(-8.7 to-18.7),and relatively constant Pb isotopic ratios((206-Pb/204Pb)i=6.74-17.884,(207Pb/204Pb)i=15.51-15.58,and(208Pb/204Pb)i=35.36-38.04),respectively.This suggests that the magmas parental to these rocks were generated from the partial melting of the ancient crust.The parental magmas to these rocks experienced a degree of fractionation of plagioclase,K-feldspar,and hornblende,possibly during rapid magma ascent.Based on these studies,we propose a reasonable model for the origin of the investigated rocks from the Xinjiang Uygur Autonomous Region of South Altyn,which involves crustal thickening,lithospheric extension,and asthenosphere upwelling,that induced crustal melting.