  Nitrogen reduction reaction (NRR) which converts nitrogen (N2) to ammonia
(NH3) normally requires harsh conditions to break the bound nitrogen bond.
Herein, via first-principles calculation we reveal that a superior NRR
catalytic activity could be obtained through anchoring atomic catalyst above a
phosphorene-like puckering surface of germanium selenide (GeSe). Through
examining the single- and double- atoms (B, Fe, W, Mo and Ru) decorated on
GeSe, we find that its rippled structure allows an intimate contact between the
deposited species and the GeSe which significantly promotes the states
hybridization. Amongst the various atomic catalyst, we predict that the Ru
dimer decorated GeSe monolayer (Ru2@GeSe) has superior catalytic activity for
the N2 fixation and reduction. Through examining the three NRR pathways
(distal, alternating and enzymatic), the distal and enzymatic pathway is both
the thermodynamically favorable with the maximum Gibbs free energy change
({\Delta}GMAX) of 0.25 and 0.26 eV, respectively. Such a superior activity
could be attributed to the filtered states of GeSe by Ru dimer which leads to
the effective activation of the adsorbed N2 bond. As an efficient near-infrared
absorber of GeSe, the Ru mediated hybridization of GeSe-Ru-N2 complex enables
an in-gap state which further broadens the absorbing window, rendering for a
broadband solar absorption and possible photocatalysis.
