We introduce the Virgo Consortium's EAGLE project, a suite of hydrodynamical simulations that follow the formation of galaxies and supermassive black holes in cosmologically representative volumes of a standard ΛCDM universe. We discuss the limitations of such simulations in light of their finite resolution and poorly constrained subgrid physics, and how these affect their predictive power. One major improvement is our treatment of feedback from massive stars and AGN in which thermal energy is injected into the gas without the need to turn off cooling or decouple hydrodynamical forces, allowing winds to develop without predetermined speed or mass loading factors. Because the feedback efficiencies cannot be predicted from first principles, we calibrate them to the present-day galaxy stellar mass function and the amplitude of the galaxy-central black hole mass relation, also taking galaxy sizes into account. The observed galaxy stellar mass function is reproduced to < ∼ 0.2 dex over the full resolved mass range, 10 8 < M * /M < ∼ 10 11 , a level of agreement close to that attained by semi-analytic models, and unprecedented for hydrodynamical simulations. We compare our results to a representative set of low-redshift observables not considered in the calibration, and find good agreement with the observed galaxy specific star formation rates, passive fractions, Tully-Fisher relation, total stellar luminosities of galaxy clusters, and column density distributions of intergalactic C iv and O vi. While the mass-metallicity relations for gas and stars are consistent with observations for M * > ∼ 10 9 M (M * > ∼ 10 10 M at intermediate resolution), they are insufficiently steep at lower masses. For the reference model the gas fractions and temperatures are too high for clusters of galaxies, but for galaxy groups these discrepancies can be resolved by adopting a higher heating temperature in the subgrid prescription for AGN feedback. The EAGLE simulation suite, which also includes physics variations and higher-resolution zoomed-in volumes described elsewhere, constitutes a valuable new resource for studies of galaxy formation.

We present the public data release of halo and galaxy catalogues extracted from the eagle suite of cosmological hydrodynamical simulations of galaxy formation. These simulations were performed with an enhanced version of the gadget code that includes a modified hydrodynamics solver, time-step limiter and subgrid treatments of baryonic physics, such as stellar mass loss, element-by-element radiative cooling, star formation and feedback from star formation and black hole accretion. The simulation suite includes runs performed in volumes ranging from 25 to 100 comoving megaparsecs per side, with numerical resolution chosen to marginally resolve the Jeans mass of the gas at the star formation threshold. The free parameters of the subgrid models for feedback are calibrated to the redshift z = 0 galaxy stellar mass function, galaxy sizes and black hole mass -stellar mass relation. The simulations have been shown to match a wide range of observations for present-day and higher-redshift galaxies. The raw particle data have been used to link galaxies across redshifts by creating merger trees. The indexing of the tree produces a simple way to connect a galaxy at one redshift to its progenitors at higher redshift and to identify its descendants at lower redshift. In this paper we present a relational database which we are making available for general use. A large number of properties of haloes and galaxies and their merger trees are stored in the database, including stellar masses, star formation rates, metallicities, photometric measurements and mock gri images. Complex queries can be created to explore the evolution of more than 10 5 galaxies, examples of which are provided in appendix. The relatively good and broad agreement of the simulations with a wide range of observational datasets makes the database an ideal resource for the analysis of model galaxies through time, and for connecting and interpreting observational datasets.

Conversion of CO 2 to value-added chemicals has been a long-standing objective, and direct hydrogenation of CO 2 to lower olefins is highly desirable but still challenging. Herein, we report a selective conversion of CO 2 to lower olefins through CO 2 hydrogenation over a ZnZrO/SAPO tandem catalyst fabricated with a ZnO-ZrO 2 solid solution and a Zn-modified SAPO-34 zeolite, which can achieve a selectivity for lower olefins as high as 80−90% among hydrocarbon products. This is realized on the basis of the dual functions of the tandem catalyst: hydrogenation of CO 2 on the ZnO-ZrO 2 solid solution and lower olefins production on the SAPO zeolite. The thermodynamic and kinetic coupling between the tandem reactions enable the highly efficient conversion of CO 2 to lower olefins. Furthermore, this catalyst is stable toward the thermal and sulfur treatments, showing the potential industrial application.

Hydrogenation of CO 2 to aromatics with selectivity of 73% among hydrocarbons at a single-pass conversion of 14% is achieved over a tandem catalyst. A thermodynamic coupling between CO 2 hydrogenation and aromatics formation was effectively conducted through the intermediate CH x O species. It was found that the presence of H 2 O and CO 2 not only facilitates aromatics production but also suppresses the formation of polycyclic aromatics, resulting in highly stable catalytic performance.