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Kitchen waste incineration technology is one of the effective technologies for achieving waste resource utilization with heat recovery and large-scale volume reduction. Pyrolysis is the most fundamental and important stage in the incineration process. Hence, this paper selects glutarimide and succinimide are abundant initial products during kitchen waste pyrolysis. Glutarimide and succinimide are the main N-containing heterocycles (33.55 wt%) in soybean protein pyrolysis from kitchen waste. The pyrolysis mechanism of glutarimide/ succinimide and the reaction pathways of NOxprecursors (NH3, HCN, and HNCO) are studied by using density functional theory (DFT) calculation. The possible pathways of NOxprecursors formation from cleavage of C-N/C-C bond caused by H-transfer and homolysis of C-N/C-C bond are proposed. The favorable pathways for the formation of HNCO have low energy barrier (430.9 kJ/mol，418.5 kJ/mol) and high reaction rate constant throughout the entire temperature range. At the same time, the hydrogenation and decomposition of HNCO have explained the trend of NH3and HCN formation under low temperature condition in pyrolysis experiment. Finally, this study theoretically proves that the yield of NH3is higher than that of HCN. This finely explains the phenomenon that NH3release is greater than HCN release in the experiment. In addition, this study found that the yield of NOxprecursor formed by glutarimide cracking is higher, and the structure of the five membered ring succinimide (minimum energy barrier value of an open loop，334.3 kJ/mol) is more stable than that of the six membered ring glutarimide (347.0 kJ/mol).

CO2hydrogenation to methanol can convert greenhouse gases and hydrogen into high value-added liquid fuels, which can be used as a promising hydrogen storage technology, it is of great significance for mitigating the greenhouse effect and energy crisis. In this paper, density functional theory is used to study the effect of Pd atomic layer coating on the activation energy barrier and selectivity in CO2hydrogenation to methanol. The Pd atomic layer coating can effectively increase the adsorption strength of the intermediate substance and the catalyst surface, the adsorption energy of H* is increased from − 3.50 to − 3.63 eV, and the adsorption energy of COOH* increases by 0.59 eV, properly increasing the adsorption energy is conducive to the progress of catalysis. The Pd atom coating is conducive to the activation and hydrogenation of CO2and the dissociation of hydrogen, the activation energy barrier of the rate-limiting step is reduced from 1.71 to 1.00 eV, and the energy barrier of H2dissociation is reduced by 0.27 eV. Cu@Pd(111) enhanced the electron delocalization and increased the catalytic activity. Besides, Pd atom coating suppresses the production of by-product CO, the adsorption energy of CO* increased from − 0.77 to − 1.76 eV, and the energy barrier for CO* production increased by 0.80 eV, inhibition of by-products is conducive to further improved methanol selectivity.