Pressure-Induced Stable Beryllium Peroxide

Abstract

Beryllium oxides, at ambient pressure, have been extensively studied due to their unique chemical bonds and applications. However, the long-desirable target beryllium peroxide (BeO) has not been reported, thus far. Currently, the application of pressure has become a powerful tool in finding unusual stoichiometric compounds with exotic properties. Here, swarm structural searches in combination with first-principles calculations disclosed that the reaction of BeO and oxygen, at pressures above 89.6 GPa, yields BeO. Interestingly, this reaction pressure is lower than the phase transition pressure (106 GPa) of pure BeO. BeO crystallizes in FeS-type structure, whose remarkable feature is that it contains peroxide group (O) with an O-O distance of 1.40 Å at 100 GPa. Notably, O is maintained in the pressure range of 89.6-300 GPa. The chemical bonding analysis shows that the uniformly distributed ionic Be-O and covalent O-O bonding network plays a key role in determining its structural stability. BeO is a direct band gap nonmetal, and its band gap becomes larger with increase of pressure, which is in sharp contrast with BaO. Moreover, phase diagram of Be-O binary compounds with various BeO (x = 1-3, y = 1-6) compositions at pressures of up to 300 GPa was reliably built. Our results are also important for enriching the understanding of beryllium oxides.

Penta- and hexa-coordinated beryllium and phosphorus in high-pressure modifications of CaBe2P2O8

“…Various molecular oxygen-rich composition compounds (BeO 2 , Be 2 O 2 , Be 2 O 4 , BeO 4 , and Be(O 3 ) 2 ) demonstrating diverse Be–O bonding situations have been recently isolated within solid noble-gas matrices 6 . Cases with Be in coordination higher than four have not been observed experimentally for inorganic compounds, though recent ab initio calculation studies on BeO 2 7 and BeO 8 have predicted the formation of BeO 6 octahedra with ionic Be–O bonding at high pressures.…”

Stoichiometry deviation in amorphous zirconium dioxide

“…The formal charge of the Zr ion in ZrO 2 is not readily increased from 4+ to 5+ as to do so would require electron removal from a new orbital (an ionization energy of $46 eV). In other similar cation systems such as MgO, 20 BeO, 21 (Ba/Sr)ZrO 3 , 22 and CeO 2 , 23 where the cation is at its highest formal charge, it has been predicted that the peroxide ion (O 2 2À )…”

Crystal Structures and Electronic Properties of Oxygen-rich Titanium Oxides at High Pressure

“…The common feature of peroxide (O2 2– ) is the single bond of oxygen atom (O–O), with the oxidization state of −1 for each oxygen atom . As the most well-known peroxide, hydrogen peroxide (H 2 O 2 ) has been widely used as disinfectant, bleaching agent, and oxidizer and sometimes also can be used as a precursor to prepare other peroxide compounds. , For the good performance in electric vehicles industries, agricultural and environmental industries, metal-containing compound with peroxide (O2 2– ) groups are usually reported in alkaline earth peroxides, such as Li 2 O 2 , , MgO 2 , and BeO 2 . Some ionic crystals containing O2 2– can be used in solid oxide fuel cells. , Unlike alkali metal earth peroxides, binary transition-metal peroxides, that is, compounds containing only metal cations and peroxide anions are rare.…”